Add a command to "refresh" the new light wallet database

[scrutinously]

With how many times I've had to tell people to delete the wallet db to fix a problem, it seems like it would be a useful feature to be able to force the wallet to resync itself (especially from its own synced fullnode). Would also be nice to have a way to force a refresh on the latest plotnft state, instead of having to remove the pool_list section from the config, then delete the wallet db, and hope for the best when it syncs again.