[pycodestyle] Whitespace after decorator (E204) (#12140)

## Summary

<!-- What's the purpose of the change? What does it do, and why? -->
This is the implementation for the new rule of `pycodestyle (E204)`. It
follows the guidlines described in the contributing site, and as such it
has a new file named `whitespace_after_decorator.rs`, a new test file
called `E204.py`, and as such invokes the `function` in the `AST
statement checker` for functions and functions in classes. Linking #2402
because it has all the pycodestyle rules.

## Test Plan

<!-- How was it tested? -->
The file E204.py, has a `decorator` defined called wrapper, and this
decorator is used for 2 cases. The first one is when a `function` which
has a `decorator` is called in the file, and the second one is when
there is a `class` and 2 `methods` are defined for the `class` with a
`decorator` attached it.

Test file:

``` python
def foo(fun):
    def wrapper():
        print('before')
        fun()
        print('after')
    return wrapper

# No error
@foo
def bar():
    print('bar')

# E204
@ foo
def baz():
    print('baz')

class Test:
    # No error
    @foo
    def bar(self):
        print('bar')

    # E204
    @ foo
    def baz(self):
        print('baz')
```

I am still new to rust and any suggestion is appreciated. Specially with
the way im using native ruff utilities.

---------

Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>

scripts/check_docs_formatted.py

@@ -86,6 +86,7 @@ KNOWN_FORMATTING_VIOLATIONS = [
     "unnecessary-class-parentheses",
     "unnecessary-escaped-quote",
     "useless-semicolon",
+    "whitespace-after-decorator",
     "whitespace-after-open-bracket",
     "whitespace-before-close-bracket",
     "whitespace-before-parameters",