* frontend: Added support for message context to localisations.
* frontend: Added string_view versions of the message lookup functions.
* frontend: Added a few more folder options to the internal UI.
* emu/softlist.cpp: Use more appropriate containers.
* Switched to Python 3 by default - this will become a requirement.
* Updated msgfmt.py for message context support.
* frontend: Show all software item info in the internal UI.
* frontend: Search alternate titles in software selection menu.
* 3rdparty/utf8proc: Updated to v2.6.1 (has several fixes).
* frontend: Added software filters for common info fields.
* frontend: Allow UI manager to hold onto persistent session data.
* frontend: Cache software lists for eight machines.
* frontend: Added support for loading localised system names.
* frontend: Add UI for selecting localised system names.
