testing/emacspeak: new aport

Emacspeak is a speech output system for Emacs. It allows visually impaired users to interact with computers by providing spoken feedback for actions carried out in Emacs.

espeak-ng is unavailable on s390x, so on that architecture, emacspeak-server-eflite is used instead of emacspeak-server-espeak.

Replaces !33697 (closed) which had aports:move and aports:upgrade tags added for some reason, and I can't seem to remove them...

Besides that, the previous MR saw the package upgraded upstream while the MR was awaiting approval, so the commit history is a bit of a mess, with me upgrading the package, and finding a solution for s390x.

I've also applied what I learned about APKBUILD style (like not using $url in source=, and making the source tarball have the filename pkgname-pkgver, instead of something else), resulting (I hope) in a cleaner and better APKBUILD.