Integrate Steam API for getting Mod locations from Steam.

Not so much a crash being produced by this, fortunately it's just showing the blocks as unnamed. I can still modify the ship and do things with it without anything untoward happening.

Anyways with the latest few changes to the way Space Engineers handles acquisition of mods from the Workshop... rather, how Steam now handles it, rather than Space Engineers retrieving them itself, the Mods folder in %APPDATA% no longer houses the mods. Of course, you still create and develop your mods from there, but Workshop mods are now stored in the following locations:

First location (the new system):

C:\Program Files (x86)\Steam\steamapps\workshop\content\244850\<mod ID>\

This is for mods published or updated after the change-over to the new Workshop system. The mod files reside there directly, not compressed, complete with a new file called metadata.mod, which is an XML file containing a single directive. Mods updated after this change-over won't contain the old modinfo.sbmi file here (since that's only used for publishing), but they WILL contain an outdated version of the below type of mod for anyone who was subscribed to the mod during the changeover, and after the author updated it! Updating the mod via ingame will automagically change the mod to this type from the outdated type below, but won't remove this stale file.

-- OR --

The second location (the old system, adapted slightly):

C:\Program Files (x86)\Steam\steamapps\workshop\content\244850\<mod ID>\<some numbers>_legacy.bin

This is just the old ZIP file mods used to come in. No metadata or anything within it, or in the same directory. Don't know what the numbers mean yet. Doesn't seem to show up in the Workshop page for the mod in question, nor in the author's Steam profile page either.

Anyways, hoping SEtoolbox gets updated to support this. For now I think I'll try zipping everything (or in the case of the older mods, renaming the existing ZIPs) and then moving them in to the %APPDATA% folder and seeing if it works or not.

The issue names no files or tests; start by locating the C# mod-discovery or import entry point and compare it with the two Steam Workshop layouts described. Done means Workshop mods in both the direct-folder and legacy .bin forms can be found and loaded instead of appearing unnamed.