Reuse follows from ActivityPub accounts

We could do something similar as #225 but instead of going through downloading the CSV file and uploading, you could just enter an ActivityPub user or URL. Mockup:

<img width="660" alt="Screenshot 2023-06-29 at 18 02 07" src="https://github.com/akirk/friends/assets/203408/3e811fd3-282c-4f39-89c5-ba344232305c">
