Automatic merge from submit-queue (batch tested with PRs 46450, 46272, 46453, 46019, 46367)
Add ClusterSelector to Ingress Controller
This pull request adds ClusterSelector to the Federated Ingress Controller ref: design #29887
This back ports the same functionality from the sync controller (merged pull #40234) in order to make this feature available across all Controllers for the 1.7 release.
cc: @kubernetes/sig-federation-pr-reviews @shashidharatd
**Release note**:
```
The annotation `federation.alpha.kubernetes.io/cluster-selector` can be used with Ingress objects to target federated clusters by label.
```
Automatic merge from submit-queue (batch tested with PRs 44942, 41258)
[Federation] Use federated informer for service controller and annotations to store lb ingress
**What this PR does / why we need it**:
This is breaking up of the PR #40296 into smaller one. please refer to #41253
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
Handles 2 tasks in #41253
Fixes issues in #27623, #35827
**Special notes for your reviewer**:
**Release note**:
```
NONE
```
cc @quinton-hoole @nikhiljindal @kubernetes/sig-federation-pr-reviews
Automatic merge from submit-queue
Federation test util fix - 1
* Make nil and empty map equivalent when testing ObjectMeta equivalence
* Add a function that waits for a particular content inside federated store
cc: @nikhiljindal @madhusudancs
