fix: user dropdown light mode UI issue

[patricio0312rev]

# [navbar] user dropdown light mode UI issue

Summary

• Styles for the hover and regular colors for the number of galleries in the user dropdown have been updated and fixed in light mode.
• The icon size for the hamburger menu button has been updated to 20px x 20px so it can match the UI.

## Views

• Mobile button size:

• Text colors in user dropdown:

## Steps to reproduce

1. Run the app in local or testing_e2e mode.
2. In desktop screen view, click on the user dropdown to see the magic ✨
3. In mobile view, check the mobile navbar to see the magic ✨

Checklist

• I checked my UI changes against the design and there are no notable differences
• I checked my UI changes for any responsiveness issues
• I checked my (code) changes for obvious issues, debug statements and commented code
• I opened a corresponding card on Clickup for any remaining TODOs in my code
• I added a short description on how to test this PR (if necessary)
• I added a storybook entry for the component that was added (if necessary)
• Documentation (if necessary)
• Tests (if necessary)
• Ready to be merged