Handle reject renew offer if position gets resized

[holzeis]

If a renew offer gets rejected, e.g. because the app was closed before the RenewOffer was successfully processed, the coordinator can't correctly process the reject at the moment.

10101/coordinator/src/node.rs

Lines 470 to 489 in 567266a

	Channel::Signed(SignedChannel {
	state: SignedChannelState::Established { .. },
	..
	}) => {
	// TODO(holzeis): Reverting the position state back from `Closing`
	// to `Open` only works as long as we do not support resizing. This
	// logic needs to be adapted when we implement resize.
	tracing::info!(
	channel_id = channel_id_hex_string,
	node_id = node_id.to_string(),
	"DLC Channel settle offer has been rejected. Setting position to back to open."
	);
	db::positions::Position::update_closing_position(
	&mut connection,
	node_id.to_string(),
	PositionState::Open,
	)?;
	}

For one the position state wouldn't get updated correctly. Fixing that isn't too hard, but then you run into the following issue, which seems to be a bit more complicated.

Failed to resize position 18: Could not propose resize DLC channel update: Invalid parameters were provided: Sum of collaterals in contract must equal total collateral in channel.