Refactor: Remove try the form builder messages on the Donations Form page

[JoshuaHungDinh]

Resolves GIVE-964

Description

These changes remove the Try the form builder button and the related banner from displaying on the Donations Form page.

The button is still visible on all v2 form adding/editing pages as well as the DonationForm page legacy view. This buttons text has also been updated to "Use the new visual form builder."

Affects

Donations Form page

Visuals

Screen.Recording.2024-07-17.at.10.34.14.AM.mov

Testing Instructions

• Verify the try the form builder button is removed and does NOT display on the Donations Form page, unless in "Legacy view".
• Verify the try the form builder banner is removed and does NOT display on the Donations Form page.
• Verify the try the form builder button is still visible on all v2 Donation Form editing & adding pages.

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]

Nice to see +1 -17. LGTM.

[rickalday]

Passed manual QA tests