fundingmanager: define stateStep, make advanceFundingState sync
fundingmanager: define stateStep, make advanceFundingState sync

This commit make the advanceFundingStateMethod synchronous. It will now
query the database for a channel's opening state, and call the method
stateStep until the channel has finished the opening procedure.

aakselrod/lnd,LightningNetwork/lnd,aakselrod/lnd,LightningNetwork/lnd