fix(python): Decode the k8s node selector and convert it as a dict.

[dashanji]

What do these changes do?

As titled.

During test, I find not all pods are scheduled to the same node.

NAME                                             READY   STATUS    RESTARTS   AGE     IP            NODE           NOMINATED NODE   READINESS GATES
coordinator-ozgjbb-6c57549cf7-hhwqt              1/1     Running   0          4m2s    10.244.1.85   kind-worker    <none>           <none>
gs-engine-ozgjbb-0                               3/3     Running   0          3m58s   10.244.1.86   kind-worker    <none>           <none>
gs-engine-ozgjbb-1                               3/3     Running   0          114s    10.244.1.87   kind-worker    <none>           <none>
gs-engine-ozgjbb-2                               3/3     Running   0          108s    10.244.1.88   kind-worker    <none>           <none>
gs-engine-ozgjbb-ozgjbb-vineyard-etcd-0          1/1     Running   0          3m58s   10.244.3.71   kind-worker2   <none>           <none>
gs-interactive-frontend-ozgjbb-8d996bc8b-ctn6x   1/1     Running   0          3m58s   10.244.3.72   kind-worker2   <none>           <none>

We should support to add the node selector to the frontend and vineyard etcd.

Related issue number

Fixes #3476

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.

Project coverage is 26.04%. Comparing base (00735b7) to head (5ff70c3).
Report is 5 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #3477       +/-   ##
===========================================
- Coverage   46.22%   26.04%   -20.18%     
===========================================
  Files         174      192       +18     
  Lines       16172    17340     +1168     
===========================================
- Hits         7476     4517     -2959     
- Misses       8696    12823     +4127     

Files	Coverage Δ
...n/graphscope/deploy/kubernetes/resource_builder.py	71.48% <0.00%> (+46.28%)	⬆️

... and 82 files with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a1f5ad2...5ff70c3. Read the comment docs.

[yecol]

Could you merge this PR? @dashanji

[dashanji]

Could you merge this PR? @dashanji

No problem.

[dashanji]

CI passed. /cc @siyuan0322