[qtc] added syntax highlighters for yaml, spec, desktop and changes

Syntax highlight files copied from kate editor. changes highlighter
modified from rpmspec highlighter.

Signed-off-by: Juha Kallioinen <juha.kallioinen@jolla.com>
(cherry picked from commit 8383a4f2f55f11a9b3cd9a9bf84281e03573657a)