RFE/C: Import/Export Repo List

N.B.: To implement @Bubu's #1484 (comment 75033022).… Perhaps can be implemented simultaneously?

• Device OS and version: Any
• Device model/manufacturer: Any
• F-Droid version (in the About screen): Any
• F-Droid privileged extension version (if installed): N/A

What did you do? (clear steps if possible)

• Add a # of repos to F-Droid from https://forum.f-droid.org/t/721/
• Force close & wipe App Data for F-Droid (which is the solution for any # of data corruption problems)

What did you expect to see?

A way to export repo list data before App Data wipe & corresponding method to import such after reopening F-Droid after that wipe.

What did you see instead?

No such options