Can now download from all banks registered on the banks/nordigen table
and write to the PostgresSQL DB (or any DB, since we're now agnostic).
Commented out most of the managers functions until the integration with
the new DB client is complete.
Set Optional relationships. Remove the DB types as dataclasses, it only
increased the verbosity of the types w/o much going for it.
Change the name Original to Transaction, since the type is the
placeholder for the rest of the transaction information.
When the credit card was correct but the bank was wrong, it was
difficul to accertain which one was wrong. Not when one fails, it will
also log what are the available options.
A bank had an offset on the date of the transactions...
It also passes the interal Bank type to the converter, to access it's
additional options before converting.
The period will only apply after the transactions have been received,
since if sent on the request, credit cards seem to use the value date
instead of the booking date, rendering the feature useless.
Also adds some robustness to the download of the transactions, by adding
a retry in case of timeout.
There is now the possibility to download the transactions for all banks
in the banks table in the DB.
`NordigenInput` parse method fully functional, and entire chain from
downloading to parsing (simple w/ converter) to writing to DB.
DbTransaction type added __conform__ to simplify writes to DB.
Get bank methods added to both `Manager` and `DatabaseClient`.
Warning: csv parser most likely not working at this point.
Issues #16 and #17
