The convenience include file CalamaresUse should DTRT and set up
all the bits needed to write Calamares branding components and
modules. So add the bits for i18n.
- The CMake modules for Calamares expect to find CMakeColors
- Also the translation support macro
- Restore CalamaresUse.cmake
- File was removed after 3.1 in db105079, but it is actually useful
for out-of-tree modules. Restore it and massage into better shape.
- Simplify by adding path to the search path (otherwise the individual
macro files would also have to switch to including with a full path).