CFG: Implemented the GetConfigInfoBlk2 function.

Added a "config" file to the CFG process service (CFG:U), and added a few default blocks to it.

Implemented GetSystemModel and GetModelNintendo2DS
=> `boost::find_if(config->block_entries, [&](SaveConfigBlockEntry const& entry)`

Also note that afaik `SaveConfigBlockEntry const& entry` is equivalent to `const SaveConfigBlockEntry& entry`, but the latter is more common in our code base.