[3.5] backport e2e WaitLeader

[ivanvc]

As discussed in multiple issues and pull requests (#16822, #15247), this is the backport of WaitLeader to the release-3.5 branch.

1. Moved Etcdctl from tests/e2e to tests/framework/e2e. This is required due to a circular dependency when requesting the status using Etcdctl from tests/framework/e2e.
2. Implemented EtcdProcess's Etcdctl, so getting a client from individual members is possible.
3. Implemented EtcdProcessCluster's WaitLeader, by adapting the code from the main branch. These required 1 and 2 to be implemented.

Please read https://github.com/etcd-io/etcd/blob/main/CONTRIBUTING.md#contribution-flow.

[k8s-ci-robot]

Hi @ivanvc. Thanks for your PR.

I'm waiting for a etcd-io member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[ahrtr]

Overall looks good to me. @ivanvc Please mark this PR as Ready for review when you feel comfortable. thx

[ivanvc]

I tested the WaitLeader functionality by replacing the sleep in corrupt_test.go with the call to WaitLeader. See commit ivanvc@07c4dcb. I can cherry-pick that commit into this PR if there's interest.
I can also squash the commits to generate a single commit. And I can also explore backporting to 3.4. Let me know.

[ahrtr]

/ok-to-test

[ahrtr]

I tested the WaitLeader functionality by replacing the sleep in corrupt_test.go with the call to WaitLeader. See commit ivanvc@07c4dcb. I can cherry-pick that commit into this PR if there's interest.

Not sure what exactly issue you are fixing in that commit. Please raise a separate issue or PR to discuss.

And I can also explore backporting to 3.4. Let me know.

Yes, we need to backport to 3.4 as well.

[ahrtr]

lgtm

Thanks

cc @serathius @fuweid