Draft: base/myar-aranath: Added version 1.33.1

Part of #286 (closed) (myar-aranath looked to be slightly easier than arktwend to start with)

This is the version of myar-aranath from the Sureai download page. There also seems to be some newer patches on the Wiki mods page (as well as a few small mods for it we could probably add)

It also looks like it's going to require the morrowind data files, as a number of required assets aren't included. It doesn't require the plugins though, so I think what we'll want to do is either add a plugins flag to base/morrowind, or create a new base/morrowind-data package out of base/morrowind, and have this depend on base/morrowind-data, and it can also block base/morrowind (since no morrowind mod will work properly with it).

Additionally, I'm not sure if the ini whitelist I copied from base/morrowind includes all the correct settings for myar-aranath. It should be compared in more detail to myar-aranath's Morrowind.ini.

It also turns out that there's a case-sensitivity bug in openmw-config where a master plugin not matching the case on disk will cause it to not be considered a master. (which is the case for a couple of the plugins here).