Move Ranged into ruff_text_size (#6919)

## Summary

The motivation here is that this enables us to implement `Ranged` in
crates that don't depend on `ruff_python_ast`.

Largely a mechanical refactor with a lot of regex, Clippy help, and
manual fixups.

## Test Plan

`cargo test`

crates/ruff_python_trivia/src/whitespace.rs

@@ -82,10 +82,11 @@ impl PythonWhitespace for str {
 
 #[cfg(test)]
 mod tests {
-    use crate::has_trailing_content;
-    use ruff_python_ast::Ranged;
     use ruff_python_parser::{parse_suite, ParseError};
     use ruff_source_file::Locator;
+    use ruff_text_size::Ranged;
+
+    use crate::has_trailing_content;
 
     #[test]
     fn trailing_content() -> Result<(), ParseError> {