Aggregate multiple channels to the same peer

[C-Otto]

If I have more than one channel to a specific peer, I don't need to balance both channels. As an example, if the first channel has 100% of the funds on my side, whereas the other channel has the same capacity with 100% of the funds on the remote side, I can route more than in the case where both channels are balanced to 50/50.

Note that larger forwards require the funds to be available in a single channel. As such, having 0.5M each in two channels is not enough to send a 1M sat payment.