Rule request: Line comment formatting rule

I'd like to have a lint rule which validates the format of line and linline comments similar to Python's PEP8 inline comment rule.

Inline comments

Correct:

statement()  // some comment

Incorrect:

statement()//some comment
statement() //some comment
statement() // some comment

Single line comments

This rule would be similar to the MARK rule added in #768, but would apply to all line comments.

Correct:

// some comment
statement()

Incorrect:

//some comment
statement()
//  some comment
statement()

Example configuration

This would be my proposal for the default values based on the Python standard and my personal preferences:

inline_comment:
  spaces_before: 2
  spaces_after: 1
line_comment:
  spaces_after: 1

I think 1 would also be an acceptable default for spaces_before.

Start by reviewing the existing MARK rule referenced in #768 and the proposed inline_comment and line_comment configuration. Define the rule's handling of the listed correct and incorrect examples, then verify that the configured spacing defaults are enforced.