Generation of L1 menu for run 3 (Part I)

First version (fairly complete) to generate the Run 3 L1 Menu. Main points:

• The L1Menu and L1TopoMenu have been merged
• There are three directories:
  • L1/Menu for the menu definition
  • L1/Config for the threshold and item definition and cabling layout, and
  • L1/Base for classes to hold the menu in place

Start assembling an MC_pp_v8 menu. The menu remains split into 2 files, a file Menu_x that defines the items, and a file Menu_x_inputs, which defines the configuration of the topo boards, muctpi and ctpin. A third Menu file exists for the legacy inputs.

For the new MC_pp_v8 menu, which I took from the 21.3 release, I also copied over a few new L1Topo algorithms.

I realize that the documentation is a bit poor at the moment. I will work on this.