Change the Channel IDs to more human readable SCID format

[Bitcoinite]

Currently LNDg uses the regular integer channel IDs. These are quite long and not very good to read from a human point of view. Many other node management tools use the more human readable format of 632384x1568x1 instead of 695313561322258433.

I propose to change the SCID format used by LNDg to display the more human friendly version of the SCIDs.