Don't copy values of ID column from sweeps to sweeps2 and let it auto-assign
values there. This is needed for the sequencer for that column to be up-to-date
with the values.
SwapHash used to be a key in the sweeps table. Now the key is outpoint which
replaces columns outpoint_txid and outpoint_index. In-memory structures and unit
tests were also updated to use outpoint as key. Outpoint is truly unique.
Deposit schema extension with a withdrawal
sweep address. If the user selects a deposit
for withdrawal the destination address of the
sweep is stored here.
