Cover watch with robustness test

[serathius]

What would you like to be added?

Spin-off from #17529

Similar to https://github.com/etcd-io/etcd/pull/17680/files we should add more failpoints into watch and simulate:

• slow watch sync
• slow watch resynchronization
• slow watch progress notify

etc

Why is this needed?

Prevent and detect other issues like #17529

[Bharadwajshivam28]

Hey @serathius can I work on this?

[serathius]

Suer, however this task is not recommended for new contributors.

[serathius]

ping @Bharadwajshivam28 any progress?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed after 21 days if no further activity occurs. Thank you for your contributions.