feat(datasource): add cpan datasource (#16545)

* feat(datasource): add cpan datasource

* Update perl versioning's readme

* Extract copystr function to lib/util/string.ts

* Remove unnecessary optional chaining

* Use registryUrl and logger.trace

* Use `perl` versioning's `isStable`

* Remove possibly unnecessary try/catch

* Use MetaCPAN API

* Use reduce

* Use maturity field for `isStable` handling

https://metacpan.org/pod/CPAN::DistnameInfo#maturity

* Revert "Extract copystr function to lib/util/string.ts"

This reverts commit 51ebf55c90a365441ad54193db1643e4c50af696.

# Conflicts:
#	lib/modules/datasource/cpan/index.ts

* Remove downloadUrl

* Extract types

* Use toMatchObject

* Improve tests

* Rename to MetaCpanSearchResult

* Rename to searchUrl

* Rename to MetaCpanFileSearchResult and add tsdoc

* Use for...of over reduce

* More safely handle the response JSON

* Use joinUrlParts

* Don't embed distribution info

* Split tsdoc comments