Internal improvements to subtyping and substitution

[kaleidawave]

• Change subtyping to use single state structure (rather than generic structures)
• Change substitution to use single immutable object for arguments
• Changes to accommodate the above
• * extends * ?, infer U and distributive extends
• Add never #136 + or folding
• Inline get_fact_by_type into the only place it is used: get_property_unbound
• Start of some try-catch stuff
• Start of inference stuff (fully won't be in this PR)
• Start of proxy stuff (fully won't be in this PR)
• Changed this object creation as an event (move logic internal to function calling)
• Allow for Func.prototype.x thing
• Flattened events
• Unknown-ness after for loops now uses closure behaviour

[kaleidawave]

Wondering whether to make events flatten and reuse them more (instead of state and ApplicationResult which sorts of duplicates information).

• This would be the state of generators and promises around nested a lot easier (just one dimensional index to record)
• Would make it easier to run half branches
• Would need to change if and for to be next

Also on the topic of events: should have an option to record all set and variable events for usage in extra diagnostics

[kaleidawave]

Still to do

• Way to disable the simple.d.ts during tests
• Get conditional and iteration events working again
  • Get array working
  • Get more exception things working
  • Something around free variable inversion
  • Does application need rest of events (unfortunately this can't be referenced contiguously during nesting so need to do something like generic chain)
• Work on more mapped types
  • Maybe get typeof and keyof working at the same type
• Rethink lookup generics. If we add typeof and keyof it might be a better way than the current #34

Done

• this setting improvements (not as an event anymore which is a little simpler)
• Class super call works (sort of)
• Functions are now hoisted

[kaleidawave]

For mapped types: could

1. Type arguments to enum TypeArgument = Explicit | PropertyKey | ...
2. Specialisation arguments have a property key field which is can use to specialise a mapped type?

However 2 is a little cheaty 1 is a workaround for the fact that can't create types without &mut TypeStore. PropertyKey wouldn't have a problem if TypeId could reference a string (possibly interned). So maybe better to pause for when I attempt #120

[kaleidawave]

Managed to squeeze some new features in here, bringing the passing tests to 235!

[kaleidawave]

This is weird. But we move

error: 
    ┌─ demo.ts:414:7
    │
410 │     function getA<T extends { a: strinthread 'main' panicked at /home/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/source-map-0.15.0/src/filesystem.rs:141:24:
index out of bounds: the len is 2 but the index is 18446744073709551615
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
g }>(p: T) {
    │                                            ---- Parameter has type T
    ·
414 │     getA({ a: 2 })
    │