[Bug 2125153] ibus does not support special Arabic compose sequences

https://bugzilla.redhat.com/show_bug.cgi?id=2125153

--- Comment #1 from Mike FABIAN  ---
For ibus-typing-booster I fixed it like this (was surprisingly easy):

https://github.com/mike-fabian/ibus-typing-booster/issues/379
https://github.com/mike-fabian/ibus-typing-booster/commit/c788401c794843a6b9...

I just had to allow other keys than Multi_key and dead keys to start a sequence
and I had to add 0x01000000 to when calculating the key value of keysyms of the
type <UXXXX>, that was all.

I hope it is equally easy in Gtk and ibus ...