Add Luganda, Twi, and Ewe

Problem/Motivation

Additional language support for Luganda, Twi, and Ewe

Steps to reproduce

These language options do not currently exist in the module settings /admin/config/regional/gtranslate

Proposed resolution

I'm supplying a patch that adds support

Remaining tasks

Testings and feedback from the community

User interface changes

Adds additional options to settings at /admin/config/regional/gtranslate

API changes

N/A

Data model changes

N/A