refactor(transformer): flatten file structure for React transform (#3604)

Purely moving files around to flatten folder structure. No substantive changes to the content of the files themselves.

crates/oxc_transformer/src/react/jsx.rs

@@ -1,5 +1,3 @@
-mod diagnostics;
-
 use std::{cell::Cell, rc::Rc};
 
 use oxc_allocator::Vec;
@@ -18,6 +16,7 @@ use crate::{
     helpers::module_imports::NamedImport,
 };
 
+use super::diagnostics;
 use super::utils::get_line_column;
 pub use super::{
     jsx_self::ReactJsxSelf,

crates/oxc_transformer/src/react/mod.rs

@@ -1,3 +1,4 @@
+mod diagnostics;
 mod display_name;
 mod jsx;
 mod jsx_self;