Improve UI consistency of Catalog filter pickers

[tylerd-canva]

Hey, I just made a Pull Request!

A few small style tweaks to make the "rest" of the filters match the Kind and Type filters at the top. It's still not perfect, note how Kind and Type have dropdowns that pop out above the page while the autocomplete-based filters reflow the content below.

Key changes:

• remove forced uppercase picker titles and option labels
• added theme background

Before

After

✔️ Checklist

• A changeset describing the change and affected packages. (more info)
• Added or updated documentation
• Tests for new functionality and regression tests for bug fixes
• Screenshots attached (for UI changes)
• All your commits have a Signed-off-by line in the message. (more info)

[backstage-goalie]

Changed Packages

Package Name	Package Path	Changeset Bump	Current Version
@backstage/plugin-catalog-react	plugins/catalog-react	patch	v1.14.1-next.2

[jhaals]

It does look a lot nicer, thank you!

[github-actions]

Thank you for contributing to Backstage! The changes in this pull request will be part of the 1.33.0 release, scheduled for Tue, 19 Nov 2024.

[jroebu14]

Hey @tylerd-canva just making you aware of this that I hope to get merged soon! Unfortunately it overlaps with the work you did here. Hope that's OK.

[tylerd-canva]

@jroebu14 Not at all! Looks like you just did a better version of what I did :) As long as the UI doesn't regress, which it doesn't seem like it does from your before/after, I'm delighted.