[CI] Add Validation to New Plugin's Metadata

[Ang-dot]

Summary

Trigger automated CI validation for new plugin's metadata

Changes

• Notion
• Added extra checkboxes for .github/PULL_REQUEST_TEMPLATE/plugin.md
• Added GH workflow to automate check for plugin_metadata.yml, will only trigger for new plugins folder, this check shall not affect existing plugin folders.
• Updated relevant documentations with the latest CI and PR templates implementation.
• Clone PR to [CI] Add Validation to New Plugin's Metadata in Python repo.

Related Changes

Description	PR
[Part 1] [Chore] Add PR Templates	#67
[Part 2] [CI] Add Validation to New Plugin's Metadata	⬅️

Dev Testing

Tested with #92 Mock PR.

• Screenshots

  Use Case	Screenshot	Result
  Changes to existing plugin folder		✅ CI check should pass as no new plugin is introduced
  No plugin_metadata.yml in new plugin folder		❌ Missing plugin_metadata.yml error
  Empty plugin_metadata.yml in new plugin folder		❌ CI check should fail on empty required fields
  Fill in plugin_name		❌ CI check should fail on other empty required fields
  Fill in author		❌ CI check should fail on other empty required fields
  Fill in short_description		❌ CI check should fail on other empty required fields
  Fill in detailed_description		❌ CI check should fail on other empty required fields
  Fill in release_date in wrong format		❌ CI check should fail on release_date format and other empty required fields
  Fill in release_date in YYYY-MM format		❌ CI check should fail on other empty required fields
  Fill in x_account_handle in wrong format		❌ CI check should fail on x_account_handle format and empty support_contact field
  Fill in x_account_handle in X account handle format		❌ CI check should fail on empty support_contact field
  Fill in support_contact in wrong format		❌ CI check should fail on contact_support format
  Fill in support_contact in email format		✅ CI check should pass as all required fields are filled and no data formatting issues
  Fill in support_contact in url format		✅ CI check should pass as all required fields are filled and no data formatting issues
  Fill in logo_url in wrong format		❌ CI check should fail on logo_url format
  Fill in logo_url in url format		✅ CI check should pass as all required fields are filled and no data formatting issues
  Fill in plugin_logo_url in wrong format		❌ CI check should fail on plugin_logo_url format
  Fill in plugin_logo_url in url format		✅ CI check should pass as all required fields are filled and no data formatting issues
  Fill in screenshots with items in wrong format		❌ CI check should fail on screenshots items format
  Fill in screenshots with items in url format		✅ CI check should pass as all required fields are filled and no data formatting issues
  Fill in demo_video_url in wrong format		❌ CI check should fail on demo_video_url format
  Fill in demo_video_url in url format		✅ CI check should pass as all required fields are filled and no data formatting issues
  Fill in documentation_url in wrong format		❌ CI check should fail on documentation_url format
  Fill in documentation_url in url format		✅ CI check should pass as all required fields are filled and no data formatting issues
  Fill in changelog_url in wrong format		❌ CI check should fail on changelog_url format
  Fill in changelog_url in url format		✅ CI check should pass as all required fields are filled and no data formatting issues
  Fill in community_url in wrong format		❌ CI check should fail on community_url format
  Fill in community_url in url format		✅ CI check should pass as all required fields are filled and no data formatting issues
  Add two new plugins in a PR		❌ One more CI pipeline is up, CI check should fail on missing plugin_metadata.yml on the second new plugin folder
  Add complete plugin_metadata.yml to second new plugin folder		✅ CI check should pass as all required fields are filled and no data formatting issues on all pipelines