Improve type checker

[krl]

The typechecker as is, is not correct enough to reliably produce correct webassembly and will need to be improved.

Various workarounds involving explicitly overriding types in typemaps, as is the case in the current codebase, only get us that far.

[aldur]

This needs discussing plus additional scoping.

[csgui]

Adding this to start collecting detailed improvements and fixes needed on the typechecker side:

1 - The inconsistency in function arguments should have been caught by the typechecker. Example below should not pass once the typechecker is fixed and can correctly detect all argument inconsistencies.

crosscheck(
    "(get-block-info? burnchain-header-hash u0 u0)",
    Err(Error::Unchecked(CheckErrors::IncorrectArgumentCount(2, 3))),
)