Fixes for building tests alone

Fixes for building tests alone

This change fixes an issue where tests cannot be built alone as well as cleans up the paths.  The general path cleanup was done so that the path format and variable names generally follow the main build of the coreclr repo.  Some highlights are:

 * Don't use Cmake as a directory name for intermediates, use intermediates instead.
 * Disable 4820 warning (this is about padding) when building tests.  Reduces noise in output significantly
 * Some fixes in typos and casing in the project files and build scripts