Crossing borders

[Sainan]

Right now, require is an impasse for the parser, so we can't have type hints, suggestions, named arguments, etc. across this border.

I have a POC for going across require on the crossing-borders branch, although that made me realise we need to first support these features for non-locals...

• Support suggestions for table properties
• Support type hints for static table functions
• Support named arguments for static table functions
• Support suggestions for (visible) global variables
• Support type mismatch warnings for (visible) global variables (Add initial type propagation for global variables #355)
• Support named arguments for (visible) global variables
• pluto_definitions (or similar) statement to allow external global variables to use these features