Author: Shamim Rezaie
MDL-67899 message: Add aria-label to the emoji picker button
http://git.moodle.org/gw?p=moodle.git;a=commit;h=a2d619941ffcbf36a04bbeb75ada3162e8dc7cc8
http://github.com/moodle/moodle/commit/a2d619941ffcbf36a04bbeb75ada3162e8dc7cc8
+ 3.8 en [toggleemojipicker,core]