Add a strict set of updates to prevent incorrect state changes and correct
usage. Supporting the transaction at the trait level prevented some cases, but
having a strict set of state change flows is better.
This bug was found while developing the signatory. The keys are read from
memory, triggering race conditions at the database, and some `Pending` states
are selected (instead of just selecting `Unspent`).
This PR also introduces a set of generic database tests to be executed for all
database implementations, this test suite will make sure writing and
maintaining new database drivers
- MintKeysDatabase
- MintQuotesDatabase
- MintProofsDatabase
- MintSignaturesDatabase
This commit splits the MintDatabase trait with 30+ methods into a series
of smaller traits, each dedicate to a specific subsystem of the mint
service.
