Support automatic bridge retrieval using Moat

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User research findings

During #18762 (closed), P1 and P2 mentioned not feeling safe sending an email to get bridges, especially using Gmail, because they understand that both things could be connected.
Someone from Russia requested this on tails-bugs@ on 2023-02-18 because they can't access Tor otherwise.

Edited Mar 15, 2023 by sajolida

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information