fix: serve all static files previously accessible from stats.jenkins.io

[lemeurherveCB]

This PR allows to continue serving all static files that were previously available from stats.jenkins.io and consumed from many places.

I've kept it KISS, copying over files (.gitignored) into the /public folder so they're serve without any more change.
This can be refined later if deemed important, the goal here is to restore broken URLs.

Tested locally.

Ref:

• To host stats.jenkins.io GSoC 2024 project in jenkins-infra helpdesk#4132 (comment)
• To host stats.jenkins.io GSoC 2024 project in jenkins-infra helpdesk#4132 (comment)

cc @dduportal @krisstern @timja

[lemeurherveCB]

(This account doesn't have permission to merge the PR, feel free to do so)

[lemeurherveCB]

Confirmed working, ex: https://stats.jenkins.io/plugin-installation-trend/view-job-filters.stats.json

[dduportal]

FYI This PR broke the production deployment: jenkins-infra/helpdesk#4132 (comment)

[dduportal]

Azcopy logs (needed to run a replay and gather the log in the post {} block) shows there are 2 files, with the same name, from different directories, to be copied:

2024/09/14 06:11:11 WARN: [P#1-T#1064] Block size 8388608 larger than maximum file chunk size, 4 MB chunk size used
2024/09/14 06:11:11 INFO: [P#1-T#1064] Starting transfer: Source "/home/jenkins/workspace/ction-jobs_stats.jenkins.io_main/dist/plugin-installation-trend/perfpublisher.stats.json" Destination "https://statsjenkinsio.file.core.windows.net/stats-jenkins-io/plugin-installation-trend/perfpublisher.stats.json". Specified chunk size 4194304
2024/09/14 06:11:11 ERR: [P#1-T#1064] UPLOADFAILED: /home/jenkins/workspace/ction-jobs_stats.jenkins.io_main/dist/plugin-installation-trend/perfpublisher.stats.json : 000 : cannot simultaneously send two files to same destination name
   Dst: https://statsjenkinsio.file.core.windows.net/stats-jenkins-io/plugin-installation-trend/perfpublisher.stats.json


2024/09/14 06:11:11 WARN: [P#1-T#1066] Block size 8388608 larger than maximum file chunk size, 4 MB chunk size used
2024/09/14 06:11:11 INFO: [P#1-T#1066] Starting transfer: Source "/home/jenkins/workspace/ction-jobs_stats.jenkins.io_main/dist/pluginversions/perfpublisher.html" Destination "https://statsjenkinsio.file.core.windows.net/stats-jenkins-io/pluginversions/perfpublisher.html". Specified chunk size 4194304
2024/09/14 06:11:11 ERR: [P#1-T#1066] UPLOADFAILED: /home/jenkins/workspace/ction-jobs_stats.jenkins.io_main/dist/pluginversions/perfpublisher.html : 000 : cannot simultaneously send two files to same destination name
   Dst: https://statsjenkinsio.file.core.windows.net/stats-jenkins-io/pluginversions/perfpublisher.html