✨ add typed watcher to ClusterCache

[ykakarap]

What this PR does / why we need it:

This PR adds support for typed watched to ClusterCache.

This will be specially useful when you want to reconcile a single object on the workload cluster.

With the current API to reconcile a single object on the workload cluster we need to reconcile an object on the mgt cluster that inturn reconciles all objects on the workload cluster.

An example use case when the new API would be useful:
Reconciling a single workload cluster node instead of queueing the CAPI Cluster to then reconciler all workload cluster nodes.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

/area clustercachetracker

[ykakarap]

/ok-to-test

[ykakarap]

/cc sbueringer

[ykakarap]

/cc vincepri

[sbueringer]

I need some time to take a look, but I think I have an idea how we could make this a (non-generic) method

[sbueringer]

/test pull-cluster-api-e2e-main

[ykakarap]

I need some time to take a look, but I think I have an idea how we could make this a (non-generic) method

The new commits take care of this. Now the PR just extend ClusterCache Watch function to also support generics. The impact to existing invocation of Watch is pretty minimal and is already addressed in this PR. Since this package is not yet released the api diff should also not be a problem.

[vincepri]

/lgtm
/assign @sbueringer

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 01a0f045ce6e30df9a6f9ef612b30adef1d7fde5

[sbueringer]

I like the direction. A few ideas to improve further

[ykakarap]

/test pull-cluster-api-e2e-main

[ykakarap]

@sbueringer Addressed all review comments.

[ykakarap]

/test pull-cluster-api-e2e-main

[sbueringer]

Last round of nits from my side

[k8s-ci-robot]

@ykakarap: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-cluster-api-apidiff-main	1c26e63	link	false	/test pull-cluster-api-apidiff-main

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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[sbueringer]

Thank you! Very nice improvement

/lgtm
/approve

/hold
In case you want further reviews, feel free to merge

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: f1c105dcf69b9452fc3132e0866255a3af1d4507

[vincepri]

Fantastic work!

/approve
/hold cancel

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: sbueringer, vincepri

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