Implement wildcard support for file searching in repository

What does this MR do?

This MR adds a new method of searching files. It was needed when we started to deal with #25921 (closed). Before doing it, we decided to add wildcard/regexp support for Gitaly repository (#277162 (closed)).

To be safe, this MR only implements to search files with wildcard path => search_files_by_wildcard_path. However, Git::Repository and GitalyClient::RepositoryService support full regexp search as it was implemented (gitaly!2262 (merged)) in that way.

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • [-] I have included a changelog entry.
  • I have not included a changelog entry because it is not a client-facing change.
• [-] Documentation (if required)
• Code review guidelines
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Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

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• Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team