Mega rewrite

[pufferfish101007]

This is a very extensive rewrite of much of the codebase. Available to test at https://pufferfish101007.github.io/hyperquark/rewrite-2024/.

Adding new blocks is now quite straightforward - prs to pufferfish101007:rewrite-2024 are welcome, especially for simpler blocks - items marked as 'easy' on the below TODO list would be good starting points

Notable changes:

• modularisation
• proper unit tests to ensure wasm (and imported js) is valid (resolves unit tests are not proper unit tests #18)
• simplifies adding new blocks
• boxed values use NaN boxing rather than tags
• ints are i32 rather than i64
• casting should always pick the best type to cast to
• clones a bit less (resolves clone is potentially overused #20)
• add compiler settings (currently mostly unused)
• auto track implemented blocks (resolves Auto-track implemented blocks #15)
• converts nans to zeros (resolves NaNs should be treated as 0 in mathematical operations #17)
• makes output types more specific (e.g. +ve/-ve, nan-ness) - based off Update improved type analysis to develop TurboWarp/scratch-vm#216
• adds own internal wasm! macro to generate code (with special pseudo-instructions for things like zeroing nans)
• github actions deploys each branch to its own gh pages subdirectory

TODO:

• operator_gt(/operator_equals?) (easy)
• control_if_else
• control_repeat_until (+ control_while and control_foreach should be implemented #13?)
• variable type specialisation (semi done)
• yielding (incl. branches & loops)
• warped custom procedures
• address TODOs in code
• other operator blocks (easy)
• pen (easy; machinery already in js)
• bubble rendering for say/think (easy; machinery already in js)
• costume rendering/looks blocks (easy; machinery already in js)
• non-warped custom blocks?
• const folding

Some tests are currently failing and are ignored in CI; these should be resolved with kaleidawave/ezno#121 and don't indicate problems in hyperquark itself.