feat(op2): add #[validate(fn)] for custom arg validation

[littledivy]

Node.js APIs written in object wrap need to throw errors like ERR_INVALID_ARG_TYPE and ERR_INVALID_CONSTRUCTOR before argument de-serialization which is not directly exposed in op2. This is currently not possible.

This PR adds custom validation hooks that run before de-serializing each argument using #[validate(fn)] attribute.

fn int(
  _scope: &mut v8::HandleScope,
  value: v8::Local<v8::Value>,
) -> Result<(), JsErrorBox> {
  if value.is_int32() {
    return Ok(());
  }

  Err(JsErrorBox::type_error("Expected int"))
}

#[op2]
impl Object {
  #[fast]
  fn n(
    &self,
    #[validate(int)]
    #[smi]
    n: u32,
  ) {
    // ...
  }
}

[bartlomieju]

LGTM

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 79.43925% with 22 lines in your changes missing coverage. Please review.

Project coverage is 80.75%. Comparing base (0c7f83e) to head (3e41cbe).
Report is 305 commits behind head on main.

Files with missing lines	Patch %	Lines
ops/op2/config.rs	32.00%	17 Missing ⚠️
ops/op2/signature.rs	75.00%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1137      +/-   ##
==========================================
- Coverage   81.43%   80.75%   -0.69%     
==========================================
  Files          97      100       +3     
  Lines       23877    28957    +5080     
==========================================
+ Hits        19445    23385    +3940     
- Misses       4432     5572    +1140     

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