NFFrontEnd function updates.

  - Instantiate overloaded functions one by one and propagate multiple overlaods.
    - OVERLOADED_CLASS is not used for overloaded functions anymore. We keep things in the cache.
    - Do not overwrite function names by the overload name.
    - Make sure we can't overlaod non function classes...
  - Do not match args while insting them.
    - We need the positional and named args separtely until we reach typing.
    - If we match and try to replace named args by values then overlaoding will not work properly.
  - Create slots after typing a function not when insting. We need the type info in the slots.
  - Added a new Call type ARG_TYPED_CALL
    - this is used while typing a call t preserve type and variablity info.
  - Track errors and print if no match only.
  - Save type info when filling args from slot defaults.
  - Handle printing of arr_typed_call.
  - Some more changes...