Fix crash when loading asl with tdta OSType

Before this commit, Krita would crash on startup if an asl file with
'tdta' OSType was put in the resource folder. This commit changes all
qFatal into exceptions that are caught later on, so there is no crash,
just a warning in the console.

(cherry picked from commit c41e868b6c61c37ba5ff10ebdf319abd0eb7c67a)
(cherry picked from commit 63dff598e064e1194f21a059926559fe13c17ebe)