Partially revert single guillemot fix (!238) for tr/f
!238 (merged) replaces the less/greater signs on AB01/AB02 with single guillemots. However, this breaks the Turkish F layout, which has no other way of entering less/greater signs.
This MR restores the previous behavior for tr/f
while maintaining the guillemot fix for other layouts. See comments on !238 (merged) for the full discussion.
This MR has not been tested, though I do not expect any regressions as it is essentially a (partial) revert.