View channel amount

[evansmj]

Stakeholder wants to be able to see the amount in each channel. This is so that we can see the state of the network.

We need a config option to show/hide these amounts. This should be in a setting page somewhere.
On top of a channel arrow, the total channel size should be displayed. get this from listchannels amount_msat. convert this into Satoshis and display it. On the bottom of the channel arrow, the amount on each side of the channel should be displayed. The text color of the side of the channel should match the node color. this comes from Node.color.