[Test] Fix build_bin_path for case sensitive FS
[Test] Fix build_bin_path for case sensitive FS

Match xenia-build and premake configuration and platform capitalization with
only first letter capitalized in filesystem (Debug, Checked, Released, Linux,
Windows, etc).
Fix xenia-build test command on linux systems.

sephiroth99/xenia,sephiroth99/xenia,sephiroth99/xenia