feat: Added example to admin-cluster.go and projectwindow.go files

[surajyadav1108]

part of the issue #15690
admin/Cluster.go file
admin/commnads/projectwindow.go file

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this does not need to be in the release notes.
• The title of the PR states what changed and the related issues number (used for the release note).
• The title of the PR conforms to the Toolchain Guide
• I've included "Closes [ISSUE #]" or "Fixes [ISSUE #]" in the description to automatically close the associated issue.
• I've updated both the CLI and UI to expose my feature, or I plan to submit a second PR with them.
• Does this PR require documentation updates?
• I've updated documentation as required by this PR.
• Optional. My organization is added to USERS.md.
• I have signed off all my commits as required by DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My build is green (troubleshooting builds).
• My new feature complies with the feature status guidelines.
• I have added a brief description of why this PR is necessary and/or what this PR solves.

[codecov]

Codecov Report

Attention: 108 lines in your changes are missing coverage. Please review.

Comparison is base (56a7bb7) 49.53% compared to head (774e6ce) 49.44%.

❗ Current head 774e6ce differs from pull request most recent head 06d1d87. Consider uploading reports for the commit 06d1d87 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #16068      +/-   ##
==========================================
- Coverage   49.53%   49.44%   -0.10%     
==========================================
  Files         269      269              
  Lines       46622    46703      +81     
==========================================
- Hits        23095    23091       -4     
- Misses      21255    21340      +85     
  Partials     2272     2272              

Files	Coverage Δ
cmd/argocd/commands/admin/cluster.go	0.00% <0.00%> (ø)
cmd/argocd/commands/projectwindows.go	0.00% <0.00%> (ø)

... and 7 files with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.