This table doesn't have `id`, except as the implicit one in Sqlite3,
so we need to add it for postgres.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
peer_htlcs has become a bit of a dumping ground: move listforwards
etc to its own file.
Also move `struct channel_info` from peer_htlcs.h to channel.h where
it more logically belongs.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
