Use template icon for .twig files
Use font’s maximumAdvancement for aligning key equivalents

Previously we would use the width of the delete glyph (⌫).
Use uuid_string_t instead of std::string(40)

This seems more appropriate and given the small size and that the former is stack allocated, there is likely no real benefit in writing directly to the std::string that we return.
Use NSIsEmptyRect instead of comparing with NSZeroRect
Remove unused include
Use gethostuuid instead of creating our own UUID