Lua: add ROM name function

[RetroEdit]

Probably named getRomName. Maybe also add getRomPath?

emu:getGameTitle() is terse and not sufficiently descriptive for things like ROM hacks.

It's possible this is redundant in a loadFile-based workflow, but it's still convenient for logging in general.

[endrift]

Unfortunately as-is this isn't possible--the core has no idea the name of the filename of ROM it's loaded. You just give the core a file handle and there's no way to retrieve that information, largely because not all file handles are backed by actual files.

[RetroEdit]

That's a very sensible architecture. I guess to account for that, the frontend would need to track not only filename, but also whether the current ROM was loaded from a file.