Partially undo [057eaa62] (Add OPT_UISTRINGS, ..)..

Partially undo [057eaa62] (Add OPT_UISTRINGS, ..)..

That commit added A_() macros for those strings which should
always be included in the binary, even without OPT_UISTRINGS.
However, because so many tests unfortunately look after string
output i have used A_() too often, just for sake the tests.

This was no good, so instead sprinkle quite of few more "if
have_feat uistrings" conditionals in the test, even if that means
that important tests like the compose hooks do not run without
OPT_UISTRINGS.