feat: [FileCollection] add function to retain multiple patterns

[christianberkman]

Description
Supersedes #8940

Add a method to FileCollection that accepts an array of strings to retain multiple patterns in the file collection.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[kenjis]

PHPStan and Rector checks in GitHub Actions failed.
Please fix them.

[kenjis]

@christianberkman You are using the PR branch name 4.6.
It is a bad practice. I cannot checkout your PR branch with gh pr checkout 8953 command, because 4.6 is the branch name already used in this main repository.
Please name another branch name like feat-something in the future.

[christianberkman]

My apologies and thank you for the clarification. Is there any use in renaming the branch now or do I start another PR with the renamed branch? Three times is the charm...

[kenjis]

Can you add a link to the section retainMultiplePatterns in the page file_collections.rst?
See https://github.com/codeigniter4/CodeIgniter4/blob/develop/contributing/documentation.rst#to-a-section

[kenjis]

There is no way to change the PR branch name.
Feel free to send another PR.