channeldb: BigSize migration, store zero-conf, scid-alias bits

This introduces a BigSize migration that is used to expand the width
of the ChannelStatus and ChannelType fields. Three channel "types"
are added - ZeroConfBit, ScidAliasChanBit, and ScidAliasFeatureBit.
ScidAliasChanBit denotes that the scid-alias channel type was
negotiated for the channel. ScidAliasFeatureBit denotes that the
scid-alias feature bit was negotiated during the *lifetime* of the
channel. Several helper functions on the OpenChannel struct are
exposed to aid callers from different packages.

The RefreshShortChanID has been renamed to Refresh.

A new function BroadcastHeight is used to guard access to the
mutable FundingBroadcastHeight member. This prevents data races.

htlcswitch/link.go

@@ -2243,7 +2243,7 @@ func (l *channelLink) UpdateShortChanID() (lnwire.ShortChannelID, error) {
 	// Refresh the channel state's short channel ID by loading it from disk.
 	// This ensures that the channel state accurately reflects the updated
 	// short channel ID.
-	err := l.channel.State().RefreshShortChanID()
+	err := l.channel.State().Refresh()
 	if err != nil {
 		l.log.Errorf("unable to refresh short_chan_id for chan_id=%v: "+
 			"%v", chanID, err)