lncli pendingchannels output: difference between `pending_closing_channels` and `waiting_close_channels`
Found an answer for this by asking the slack community:


pending_closing_channels: waiting for confirmation blockheight after cooperative closing and publishing on the blockchain (standard case)
waiting_close_channels: closing request being processed
'pending_force_closing_channels': waiting for confirmation blockheight of unilaterally closing the channel (Commitment Transaction)