nls: add compose sequence for capital schwa, and delete a deviant one

This sequence has already been defined in the iso8859-9e compose file meant for the Azerbaijani locale, yet for the longest time, only the lowercase form has existed in the en_US.UTF-8 master compose file. This patch adds one sequence for Latin Capital Letter Schwa for the Azerbaijani language.

Additionally, the sequence in the pt_BR.UTF-8 locale for capital schwa has been removed as it uses two lowercase e's as part of its sequence, which in practice would make typing both Multi_key e e and Multi_key E E output capital schwa.