[11.13] Add support for Advanced Search API

[macbookandrew]

Updated version of @IAL32’s work in https://github.com/GitLabPHP/Client/pull/696:

• Removed pagination as requested
• Added groups
• Added projects

[macbookandrew]

@GrahamCampbell what should I do about the failing phpstan tests?

They’re in a file that I didn’t touch; I just ran phpstan locally against the 11.13 branch and see the same failure there, so it doesn’t seem to be related to these changes.

Thanks!