[Delete Wallet] Remove bdk/lwk wallet db on delete

[i5hi]

We removed deleting wallet db because of the issue with interference with sync

We have to ensure that there is no ongoing sync when a wallet is being deleted and bring back removal of bdk/lwk db files.

[ethicnology]

Once #1455 is merged it should be safer since the sync will happens only if the user Pull or if the background task is happening (~20m)