Fix missing styles on the Brand Plugin dashboard

[arunshenoy99]

Proposed changes

This fixes an issue introduced by #64 that was preventing the Brand Plugin dashboard styles from loading for the Web, Crazy Domains, and Mojo plugins. Test failure caught this. I've updated the code to check for the active brand plugin page from the container instead of a hardcoded list of brand names.

Type of Change

Production

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Dependency update
• Refactoring / housekeeping (changes to files not directly related to functionality)

Development

• Tests
• Dependency update
• Environment update / refactoring
• Documentation Update

Video

Checklist

• I have read the CONTRIBUTING doc
• I have viewed my change in a web-browser
• Linting and tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments