Remove VModInfo for now

Remove VModInfo for now

VModInfo currently is only used to track which virtual modifiers were
declared in the file which owns the VModInfo. This, in turn, is only
used in ResolveVirtualModifier, which in turn is only used to resolve
the virtualModifier field in an interpret statement (compat.c). In other
words, it is used to ensure that interprets can only use a vmod which
was declared in the same map.

We remove this now, because it doesn't do much and distracts from other
changes; we will later re-add it properly. Specificly, we will make it
so that virtual modifiers are not the exception in that they modify the
keymap directly, instead of keeping the changes in some *Info struct and
commiting them to the keymap at the end of the compilation. (This is bad
because if a vmod is added to the keymap, and then the compilation of
this specific file fails, the change sticks around nonetheless).

Signed-off-by: Ran Benita <ran234@gmail.com>