rvr refractor main setup plots

[rubyvanrooyen]

Rather aggressive refactoring, with the hope that adjusting the input parameters will be simpler in future

Breaking out parser sub-functions from main that sets up plotting parameters from input arguments All added into main to have a one location for update Some duplication of code remains, but should relatively easy to read

Updates to functionality:

• No longer allowed to have both --ant-num and --ant with ant-num silently acting to replace ant
shadems: error: argument --ant: not allowed with argument --ant-num

• Issue a warning if only one antenna is listed for --ant UserWarning: Suggested usage: '--baseline m010-*' to select all baselines to m010.

• Extensive testing ./check-shadems-functionality.sh msfiles/small.ms -c -e -x

Want to look at set up a proper test MS before making anymore changes

[o-smirnov]

Just one last test with the Caracal pipeline, then I'll confirm.

[rubyvanrooyen]

@o-smirnov I cleaned up cli(), happy to for you to merge please