feat: support harbor project & group integration

[BoxBoxJason]

Description of your changes

This PR adds a new supported integration for projects & groups: Harbor.

This comes with two new managed resources (the project & group Harbor Integration) API declarations.
Creates complete abstract clients to interact with the gitlab API for these. (I tried mutualizing as much as I could the functions).
Creates the controller logic to handle and reconcile these new resources.

This comes packaged with a very complete unit tests coverage (mostly AI generated to achieve extensive testing). We have ~81% coverage on the controller functions & ~90% coverage on the clients functions.

Closes #314

I have:

• Read and followed Crossplane's contribution process.
• Followed the git conventional commit message format.
• Made sure all changes are covered by proper tests, reaching a coverage of at least 80% when applicable.
• Run make reviewable to ensure this PR is ready for review.
• Added backport release-x.y labels to auto-backport this PR if necessary.

How has this code been tested

I have:

• Successfully built and ran the provider locally against a kubernetes cluster.
• Successfully created, updated, and deleted resources of the types I changed / created.
• Ensured reconciliation loops for the changed / created resource complete without error.
  • Creation
  • Update
  • Deletion
• Deleted the resource on the app side to ensure the provider correctly handles
  unexpected drift. (should result in recreation of the resource if applicable)
• Updated the resource on the app side to ensure the provider correctly handles
  unexpected drift. (should result in an update of the resource if applicable)

[BoxBoxJason]

Requires #317

[henrysachs]

@BoxBoxJason could you rebase this one too? as your changes are now on master

[BoxBoxJason]

Hey there @henrysachs !

The rebase was just performed for this branch !

Thanks for your reviews !