Feature: Native SSA Support

Tasks:
* [x] client.Apply: https://github.com/kubernetes-sigs/controller-runtime/issues/347
* [x] https://github.com/kubernetes-sigs/controller-runtime/pull/3253
* [x] k/k: interface for ApplyConfigurations: https://github.com/kubernetes/kubernetes/issues/118138
* [x] Support for Unstructured
* [x] fake client support for SSA: https://github.com/kubernetes-sigs/controller-runtime/issues/2341
* [x] https://github.com/kubernetes-sigs/controller-runtime/pull/2981
* [x] k/k: extend tracker: https://github.com/kubernetes/kubernetes/pull/132004
* [ ] SubResource Apply: https://github.com/kubernetes-sigs/controller-runtime/pull/3321
* [x] Real client
* [x] Deprecate client.Apply again (see: https://github.com/kubernetes-sigs/controller-runtime/pull/3307)
* [ ] Fake client
* [ ] Non-Status subresources

Tasks controller-tools:
* [x] Generation of ApplyConfigurations: https://github.com/kubernetes-sigs/controller-tools/pull/818
* [x] Generation of Extract functions (details: https://github.com/kubernetes-sigs/controller-runtime/issues/3183#issuecomment-2782827772): https://github.com/kubernetes-sigs/controller-tools/pull/1346

Start with the open SubResource Apply work in controller-runtime/pull/3321 and its fake-client portion. Review the existing fake client SSA support and the linked Kubernetes tracker changes, then determine what is needed for non-Status subresources. Done means the fake client supports Apply for those subresources and the relevant behavior is covered by tests.

Written by the indexing model from the issue text.