* Add PostgreSQL support for mint and wallet
* Fixed bug to avoid empty calls `get_proofs_states`
* Fixed SQL bug
* Avoid redudant clone()
* Add more tests for the storage layer
* Minor enhacements
* Add a generic function to execute db operations
This function would log slow operations and log errors
* Provision a postgres db for tests
* Update deps for msrv
* Add postgres to pipeline
* feat: add psgl to example and docker
* feat: db url fmt
---------
Co-authored-by: thesimplekid <tsk@thesimplekid.com>
* Working on a better database abstraction
After [this question in the chat](https://matrix.to/#/!oJFtttFHGfnTGrIjvD:matrix.cashu.space/$oJFtttFHGfnTGrIjvD:matrix.cashu.space/$I5ZtjJtBM0ctltThDYpoCwClZFlM6PHzf8q2Rjqmso8)
regarding a database transaction within the same function, I realized a few
design flaws in our SQL database abstraction, particularly regarding
transactions.
1. Our upper abstraction got it right, where a transaction is bound with `&mut
self`, so Rust knows how to handle its lifetime with' async/await'.
2. The raw database does not; instead, it returns &self, and beginning a
transaction takes &self as well, which is problematic for Rust, but that's not
all. It is fundamentally wrong. A transaction should take &mut self when
beginning a transaction, as that connection is bound to a transaction and
should not be returned to the pool. Currently, that responsibility lies with
the implementor. If a mistake is made, a transaction could be executed in two
or more connections.
3. The way a database is bound to our store layer is through a single struct,
which may or may not internally utilize our connection pool. This is also
another design flow, in this PR, a connection pool is owned, and to use a
connection, it should be requested, and that connection is reference with
mutable when beginning a transaction
* Improve the abstraction with fewer generics
As suggested by @thesimplekid
* Add BEGIN IMMEDIATE for SQLite
The primary purpose of this new crate is to have a common and shared codebase
for all SQL storage systems. It would force us to write standard SQL using best
practices for all databases.
This crate has been extracted from #878
