allow disabling rules via comments

[psteinroe]

we should add a general purpose comment parsing solution:

• a comment directly above a statement should be included in the statement: change in statement_splitter
• add an "annotation" struct in the workspace that uses the lexer to extract annotations within comments for a statement

Discussed in #299

^{Originally posted by mplanchard April 4, 2025}
The default ban on dropping columns is great, but it would be nice in cases where we know the drop is safe to be able to indicate that that particular drop should be ignored. Is this possible?