This patch introduces a helper class for SQfLite encryption related operations.
Most matrix clients will encrypt their sqlite database at rest. Since
this is a quite fragmented task using the Flutter sqlite ecosystem, this
helper aims to simplify some more complex operations.
It in particular helps with the following tasks :
- loading the correct shared objects / dynamic libraries for sqlcipher
- check whether a database is encrypted
- migrate an unencrypted SQLite database to SQLCipher
- apply the cipher to a database while opening it and ensure it loads
This code is not exactly matrix related, though presumably any matrix
client will use parts of it.
Possible regressions :
- `package:sqlite3` became a direct dependency. As of now it already was a
transitive dependency of the SDK itself.
Signed-off-by: The one with the braid <info@braid.business>