In this commit, we move the location where we restore the channel status
to within the `RestoreChannelShells` method itself. Before this commit,
we attempted to use `ApplyChanStatus` which creates a DB transaction and
relies on a fully populated channel state, which in the restoration
case, we don't yet have.
The `openChannelShell` method now includes the new config information
within the open channel shells. Additionally, we now properly re-derive
all keys from our local chan config so they're useable immediately in
the channel state machine.
We extend the `chanDBRestorer.RestoreChansFromSingles` method to also
add the new channels to the chain arbitrator once they've been restored
on disk. We do this in order to ensure that we catch the channel closure
on chain once the DLP protocol beings.