Fix: form builder sidebar tabs for WP 6.5 compatibility

[jonwaldstein]

Resolves GIVE-600

Description

The form builder sidebar tabs have been visually compromised after updated to WP 6.5. This PR preserves the backwards compatible styles.

For context, it appears the new version of Gutenberg updated some styles which affected this. To preserve those styles I went back a version to grab what we were relying on and updated our own stylesheet.

Affects

The form builder sidebar tab styles

Visuals

WP 6.5

WP 6.4

WP 6.3

Testing Instructions

• Install WP 6.5
• Use this branch / zip to check the form builder sidebar tabs
• Check on a couple previous WP versions as well.

Pre-review Checklist

• Acceptance criteria satisfied and marked in related issue
• Relevant @unreleased tags included in DocBlocks
• Includes unit tests
• Reviewed by the designer (if follows a design)
• Self Review of code and UX completed

[pauloiankoski]

Looks good 🌈