templates: support string patterns in template language #5692

Job	Run time
check (protos)	49s
build (no git)	1m 30s
test (linux-aarch64-gnu)	6m 45s
test (macos-x86_64)	10m 19s
test (linux-x86_64-gnu)	5m 37s
test (windows-x86_64)	14m 30s
nix flake (ubuntu-24.04-arm)	7m 33s
check (mkdocs)	14s
test (windows-aarch64)	16m 55s
test (macos-aarch64)	4m 37s
check (codespell)	11s
nix flake (macos-14)	8m 38s
nix flake (ubuntu-24.04)	7m 59s
check (latest mkdocs, optional)	17s
check (zizmor)	30s
check (rustfmt)	22s
check (clippy)	1m 28s
check (doctests)	3m 8s
check (cargo-deny, sources)	31s
check (cargo-deny, bans)	30s
check (cargo-deny, advisories)	30s
check (Cargo.lock dependency count)	6s
check (cargo-deny, licenses)	27s
required checks (merge queue)	0s
	1h 33m 26s

Provide feedback