Codec-related refactorings and quality of life improvements

[neysofu]

This (draft, at the time of writing) PR makes the following changes in an attempt to improve code quality in areas of the codebase that are related to svm-codec:

• Reduce macro usage; implement a trait BytesPrimitive: AsRef<[u8]> + AsMut<[u8]> for Address, TemplateAddr, State and others.
• Leverage the new BytesPrimitive trait to implement common features with generics, as well as unifying encoding and decoding logic.
• Unify encode_xyz and decode_xyz functions in svm_codec under a Codec trait. This helps discoverability, can benefit from writing generic unit tests and improves error handling.
• Overhaul the wasm API. Rewrite buffering logic with safety in mind and greatly reduce amount of code.
• Exploratory work for providing a Typescript typed wrapper around svm_codec::api::wasm.

[neysofu]

I've turned BytesPrimitive::len() into an associated constant BytesPrimitive::N and also fixed all other issues, I think. I'll wait for CI.