[pydoclint] Implement docstring-missing-exception and docstring-extraneous-exception (DOC501, DOC502) (#11471)

## Summary

These are the first rules implemented as part of #458, but I plan to
implement more.

Specifically, this implements `docstring-missing-exception` which checks
for raised exceptions not documented in the docstring, and
`docstring-extraneous-exception` which checks for exceptions in the
docstring not present in the body.

## Test Plan

Test fixtures added for both google and numpy style.

scripts/add_plugin.py

@@ -48,7 +48,7 @@ mod tests {
         let snapshot = format!("{}_{}", rule_code.as_ref(), path.to_string_lossy());
         let diagnostics = test_path(
             Path::new("%s").join(path).as_path(),
-            &settings::Settings::for_rule(rule_code),
+            &settings::LinterSettings::for_rule(rule_code),
         )?;
         assert_messages!(snapshot, diagnostics);
         Ok(())