fix: Search raw identifiers without prefix
When we find references/usages of a raw identifier, we should disregard `r#` prefix because there are keywords one can use without the prefix in earlier editions (see #13034; this bug is actually fallout from the PR). `name`, the text we're searching for, has already been stripped of the prefix, but the text of nodes we compare it to hasn't been.
The second commit is strictly refactoring, I can remove it if it's not much of value.
88b3d9f6f4