Split remote key in components config file into base and component names

[pchakraborty]

Currently, in a components file, we have entries like

  remote: git@github.com:GEOS-ESM/GMAO_Shared.git

Idea is to replace that line with the following two

  remote_base: git@github.com:GEOS-ESM
  component_name: GMAO_Shared.git

This should help in two ways

1. We can use YAML anchors to specify the remote_base once
2. Since we are specifying remote_base once, it should be easier to switch between remotes (e.g. when sharing code with others without going through GitHub)