Feature: Handle orphaned forms

[alaca]

Description

This PR adds functionality enabling users to associate orphaned donation forms with a campaign. Also, the donation form entity is added.

Affects

Admin settings

Visuals

Screen.Recording.2025-04-15.at.17.49.33.mov

Testing Instructions

You can delete all campaign form relations by running this query:

delete from wp_give_campaign_forms;

Go to Settings > Advanced > Advanced Options and enable the Orphaned Donation Forms option
Then go to Tools > Data > Orphaned donation forms

Select forms and associate them with a campaign

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

[jonwaldstein]

@alaca awesome job, I just tested this locally and it worked great! I just added a couple suggestions for default meta values and one question, otherwise this is ready for QA 🌈

[rickalday]

Passed QA tests.