More abstractions please!

Added dynamic function dispatch which allows for functions to take in
other functions as arguments, of course, this isn’t possible at all in
normal scratch, so actually FunctionLiteral gets turned into an
integer and a custom dispatch function gets created for every function
literal’s signature which allows for a binary search to call the actual
function

Also made HeapConversion reuse stack slots instead of allocating one
for every variable(mostly by AI)