Get rid of SQLite and use DynamoDB

[darioackermann]

SQLite is not designed for NFS and random errors such as "database image is malformed", "database is busy" etc. need to be expected. These errors resolve after some "cooldown" time, however prevents the user (usually) from logging in into vaultwarden.

As the issue comes with locking issues on NFS, the only way to get rid of this problem is to rewrite Vaultwarden to use DynamoDB. Following crates could be an acceptable remedy without using too much time:

• https://github.com/gabotechs/dynarust
• https://github.com/softprops/dynomite

Please see also #1 (comment)