add support for CRD annotations and labels in kube-derive

[verokarhu]

This PR adds support for setting annotations and labels on kube-derive generated CRDs.

Motivation

Writing Cluster API providers requires setting specific labels on the CRD: https://cluster-api.sigs.k8s.io/developer/providers/contracts#api-version-labels

Solution

New annotation and label fields are added to kube-derive which can take a tuple of two strings as an argument.

[codecov]

Codecov Report

Attention: Patch coverage is 88.46154% with 3 lines in your changes missing coverage. Please review.

Project coverage is 75.3%. Comparing base (b0538cb) to head (7d0f590).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
kube-derive/src/custom_resource.rs	88.5%	3 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #1631     +/-   ##
=======================================
+ Coverage   75.3%   75.3%   +0.1%     
=======================================
  Files         82      82             
  Lines       7346    7371     +25     
=======================================
+ Hits        5528    5550     +22     
- Misses      1818    1821      +3     

Files with missing lines	Coverage Δ
kube-derive/src/lib.rs	0.0% <ø> (ø)
kube-derive/tests/crd_schema_test.rs	96.9% <ø> (ø)
kube-derive/src/custom_resource.rs	82.3% <88.5%> (+0.9%)	⬆️

[clux]

Hey, thanks for this. I think the general setup is sensible, but have one improvement request for the attribute API, which i think can be nicer.

(Also if you want, when we get it done well, feel free to also do annotation support).

[verokarhu]

I rewrote the solution so the values are now passed as a two-string tuple. Also added the annotation support.

[clux]

very nice. tests and doc look much clearer now. thanks for taking the time to do this.