Donation Appeal — Migrate K9 Preferences to Config Store

The original donation appeal stored variables in K9.kt, a class we're moving away from. During this project, a new config store was created for storing data related to the new donation appeal. However, the logic for displaying this view still relies on the storage coming from k9.kt.

This is a stretch goal. We will likely release the donation appeal feature before we complete this.

AC:

• Move the donation appeal/funding preferences from k9.kt to the FundingConfigStore implementation.
• Create a migration to pull in the old data for new users
• Create tests for both the migration and the new values in the funding config store