Fates testmod on fates_next_api is setting a coldstart, but we also have FatesCold

The base Fates testmod on the fates_next_api is setting a coldstart, but this overrides the reason to have a FatesCold testmod. I'd rather have the fact that it's a coldstart be defined in the testmod name. And any testmods that inherit from FatesCold also have that in their name. This just makes it all more clear when you look at a test and/or a test list.

@rgknox