crypto/verify refactor?

[bplatz]

There is a question if crypto/verify should be doing JSON parsing, or if that should be handled separately.

Once some additional changes in fluree/server land, including how it is used in middleware, it can be examined.

I think at this point the way it is working currently is OK.

[bplatz]

Also to point out - this function is only used internally, so whatever choice is decided it will not affect anything touching end users.