Remove Memory database

[thesimplekid]

We've discussed removing the memory database from the mint database. In cases where an in memory database is desired an in memory sql db could be used and it removed the need for us to maintain another db within cdk. I think this is fairly obvious for the mint should be also do it for the wallet?

cc @crodas

[crodas]

I have started working on it and will submit a PR shortly. In my PR, SQLite with :memory: is being used, with migration every time the Memory Database is being created.

The main benefit would be fewer things to maintain, specially when transactions changes are added to the database, it will be implemented already by the SQLite driver.

Does this sound like a plan?

[thesimplekid]

Does this sound like a plan?

Yes I'm happy we do this for both mint and wallet unless, anyone thinks we should keep it?