Handle BOOKMARK events in watch.py

[note35]

/kind feature

What this PR does / why we need it:

This PR implements the TODO in watch.py to handle BOOKMARK events. Previously, BOOKMARK events were ignored.

Changes included:

1. Updated unmarshal_event to extract and update resource_version when receiving BOOKMARK events.
2. Refactored unmarshal_event using guard clauses to improve readability and reduce nesting.
3. Added unit tests to verify bookmark handling.

Which issue(s) this PR fixes:

It fixes TODO in kubernetes/watch/watch.py, I think no issue is created for this.

Special notes for your reviewer:

Verified with python -m unittest kubernetes/watch/watch_test.py
Applied flake8 and isort on impacted lines. (No <= 80 characters limitation.)

Does this PR introduce a user-facing change?

Optimized Watch client to handle BOOKMARK events' resource version.

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

N/A

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: note35 / name: Kir (4618df8)

[k8s-ci-robot]

Welcome @note35!

It looks like this is your first PR to kubernetes-client/python 🎉. Please refer to our pull request process documentation to help your PR have a smooth ride to approval.

You will be prompted by a bot to use commands during the review process. Do not be afraid to follow the prompts! It is okay to experiment. Here is the bot commands documentation.

You can also check if kubernetes-client/python has its own contribution guidelines.

You may want to refer to our testing guide if you run into trouble with your tests not passing.

If you are having difficulty getting your pull request seen, please follow the recommended escalation practices. Also, for tips and tricks in the contribution process you may want to read the Kubernetes contributor cheat sheet. We want to make sure your contribution gets all the attention it needs!

Thank you, and welcome to Kubernetes. 😃

[yliaog]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: note35, yliaog

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• kubernetes/base/OWNERS [yliaog]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment