Expand test coverage for pkg/util/compression

[blt]

What does this PR do?

This commit is motivated by the potential end state in spike PR #45519.
That is, if we want to make non-trivial changes to this package systematic
testing of the package is warranted. I have introduced tests to confirm that
for all the strategies supported by this package:

• the identity b == decompress(compress(b)) holds
  • that this is true also for zstd cgo/nocgo crossed
• empirical confirmation of the CompressBound calculations
• tests for resource management by the streaming compression

This commit includes fixes for the following:

• zlib CompressBound: Changed from 13 to 16 bytes overhead
• gzip CompressBound: Changed from 18 to 33 bytes overhead
• zstd CGO: Fixed write-after-close bug by adding a wrapper with state tracking

[blt]

• Expand test coverage for pkg/util/compression #45534 👈 (View in Graphite)
• main

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[agent-platform-auto-pr]

Go Package Import Differences

Baseline: 8766844
Comparison: ab6aa69

binary	os	arch	change
security-agent	linux	amd64	+4, -0 +github.com/klauspost/compress +github.com/klauspost/compress/fse +github.com/klauspost/compress/huff0 +github.com/klauspost/compress/zstd
security-agent	linux	arm64	+4, -0 +github.com/klauspost/compress +github.com/klauspost/compress/fse +github.com/klauspost/compress/huff0 +github.com/klauspost/compress/zstd
security-agent	windows	amd64	+4, -0 +github.com/klauspost/compress +github.com/klauspost/compress/fse +github.com/klauspost/compress/huff0 +github.com/klauspost/compress/zstd

[agent-platform-auto-pr]

Static quality checks

❌ Please find below the results from static quality gates
Comparison made with ancestor 8766844
📊 Static Quality Gates Dashboard

Error

	Quality gate	Change	Size (prev → curr → max)
❌	agent_msi (on wire)	+268.0 KiB (0.18% increase)	143.152 → 143.414 → 143.300

Gate failure full details

Quality gate	Error type	Error message
agent_msi	StaticQualityGateFailed	�[91mstatic_quality_gate_agent_msi failed! Wire size 143.4 MB exceeds limit of 143.3 MB by 116.8 KB�[0m

Static quality gates prevent the PR to merge!
You can check the static quality gates confluence page for guidance. We also have a toolbox page available to list tools useful to debug the size increase.

Successful checks

Info

	Quality gate	Change	Size (prev → curr → max)
✅	agent_deb_amd64	+8.41 KiB (0.00% increase)	752.511 → 752.519 → 754.830
✅	agent_deb_amd64_fips	+12.41 KiB (0.00% increase)	701.180 → 701.192 → 704.000
✅	agent_heroku_amd64	+4.03 KiB (0.00% increase)	326.974 → 326.977 → 329.530
✅	agent_rpm_amd64	+8.41 KiB (0.00% increase)	752.495 → 752.503 → 754.800
✅	agent_rpm_amd64_fips	+12.41 KiB (0.00% increase)	701.164 → 701.176 → 703.990
✅	agent_rpm_arm64	+4.41 KiB (0.00% increase)	731.268 → 731.272 → 737.340
✅	agent_rpm_arm64_fips	+12.41 KiB (0.00% increase)	683.256 → 683.268 → 688.480
✅	agent_suse_amd64	+8.41 KiB (0.00% increase)	752.495 → 752.503 → 754.800
✅	agent_suse_amd64_fips	+12.41 KiB (0.00% increase)	701.164 → 701.176 → 703.990
✅	agent_suse_arm64	+4.41 KiB (0.00% increase)	731.268 → 731.272 → 737.340
✅	agent_suse_arm64_fips	+12.41 KiB (0.00% increase)	683.256 → 683.268 → 688.480
✅	docker_agent_amd64	+8.4 KiB (0.00% increase)	814.612 → 814.620 → 817.140
✅	docker_agent_arm64	+4.41 KiB (0.00% increase)	817.976 → 817.980 → 824.020
✅	docker_agent_jmx_amd64	+8.42 KiB (0.00% increase)	1005.491 → 1005.499 → 1008.020
✅	docker_agent_jmx_arm64	+4.41 KiB (0.00% increase)	997.574 → 997.578 → 1003.620
✅	docker_cluster_agent_amd64	+4.03 KiB (0.00% increase)	181.112 → 181.116 → 181.120
✅	iot_agent_deb_arm64	+4.03 KiB (0.01% increase)	40.135 → 40.139 → 40.920
✅	iot_agent_deb_armhf	+4.02 KiB (0.01% increase)	40.705 → 40.709 → 41.030

12 successful checks with minimal change (< 2 KiB)

	Quality gate	Current Size
✅	docker_cluster_agent_arm64	196.918 MiB
✅	docker_cws_instrumentation_amd64	7.135 MiB
✅	docker_cws_instrumentation_arm64	6.689 MiB
✅	docker_dogstatsd_amd64	38.840 MiB
✅	docker_dogstatsd_arm64	37.128 MiB
✅	dogstatsd_deb_amd64	30.059 MiB
✅	dogstatsd_deb_arm64	28.204 MiB
✅	dogstatsd_rpm_amd64	30.059 MiB
✅	dogstatsd_suse_amd64	30.059 MiB
✅	iot_agent_deb_amd64	43.037 MiB
✅	iot_agent_rpm_amd64	43.038 MiB
✅	iot_agent_suse_amd64	43.038 MiB

On-wire sizes (compressed)

	Quality gate	Change	Size (prev → curr → max)
❌	agent_msi	+268.0 KiB (0.18% increase)	143.152 → 143.414 → 143.300
✅	agent_deb_amd64	-45.44 KiB (0.02% reduction)	183.949 → 183.905 → 184.810
✅	agent_deb_amd64_fips	+49.43 KiB (0.03% increase)	172.616 → 172.664 → 173.790
✅	agent_heroku_amd64	neutral	87.157 MiB → 88.450
✅	agent_rpm_amd64	-5.39 KiB (0.00% reduction)	186.830 → 186.824 → 188.160
✅	agent_rpm_amd64_fips	-10.23 KiB (0.01% reduction)	175.731 → 175.721 → 176.600
✅	agent_rpm_arm64	-8.96 KiB (0.01% reduction)	168.625 → 168.616 → 169.930
✅	agent_rpm_arm64_fips	-6.83 KiB (0.00% reduction)	159.172 → 159.165 → 160.550
✅	agent_suse_amd64	-5.39 KiB (0.00% reduction)	186.830 → 186.824 → 188.160
✅	agent_suse_amd64_fips	-10.23 KiB (0.01% reduction)	175.731 → 175.721 → 176.600
✅	agent_suse_arm64	-8.96 KiB (0.01% reduction)	168.625 → 168.616 → 169.930
✅	agent_suse_arm64_fips	-6.83 KiB (0.00% reduction)	159.172 → 159.165 → 160.550
✅	docker_agent_amd64	neutral	276.622 MiB → 277.400
✅	docker_agent_arm64	+15.32 KiB (0.01% increase)	264.050 → 264.065 → 266.040
✅	docker_agent_jmx_amd64	-3.21 KiB (0.00% reduction)	345.262 → 345.258 → 346.020
✅	docker_agent_jmx_arm64	+14.66 KiB (0.00% increase)	328.668 → 328.682 → 330.660
✅	docker_cluster_agent_amd64	+2.14 KiB (0.00% increase)	63.994 → 63.996 → 64.490
✅	docker_cluster_agent_arm64	-4.78 KiB (0.01% reduction)	60.256 → 60.252 → 61.170
✅	docker_cws_instrumentation_amd64	neutral	2.994 MiB → 3.330
✅	docker_cws_instrumentation_arm64	neutral	2.726 MiB → 3.090
✅	docker_dogstatsd_amd64	neutral	15.031 MiB → 15.820
✅	docker_dogstatsd_arm64	-2.41 KiB (0.02% reduction)	14.356 → 14.354 → 14.830
✅	dogstatsd_deb_amd64	neutral	7.947 MiB → 8.790
✅	dogstatsd_deb_arm64	neutral	6.826 MiB → 7.710
✅	dogstatsd_rpm_amd64	neutral	7.958 MiB → 8.800
✅	dogstatsd_suse_amd64	neutral	7.958 MiB → 8.800
✅	iot_agent_deb_amd64	neutral	11.290 MiB → 12.040
✅	iot_agent_deb_arm64	neutral	9.650 MiB → 10.450
✅	iot_agent_deb_armhf	neutral	9.843 MiB → 10.620
✅	iot_agent_rpm_amd64	neutral	11.309 MiB → 12.060
✅	iot_agent_suse_amd64	neutral	11.309 MiB → 12.060