fix: set height for navbar menu items

[patricio0312rev]

# [navbar] white space between navbar line and selected/hover lines

Summary

• The height for the navbar menu items has been set as 72px, just as in our Figma file.
• As an addition, the class names for dark mode on the galleries page have been added.

## Steps to reproduce

1. Run the app in local or test_e2e mode.
2. Go to /galleries page and 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