refactor(formatter): improve AstNode and AstNodes (#14686)

Reorganize it so that we can impl some useful methods for them

Author: Dunqing

.github/generated/ast_changes_watch_list.yml

@@ -43,8 +43,8 @@ src:
   - 'crates/oxc_ast_visit/src/generated/utf8_to_utf16_converter.rs'
   - 'crates/oxc_ast_visit/src/generated/visit.rs'
   - 'crates/oxc_ast_visit/src/generated/visit_mut.rs'
-  - 'crates/oxc_formatter/src/generated/ast_nodes.rs'
-  - 'crates/oxc_formatter/src/generated/format.rs'
+  - 'crates/oxc_formatter/src/ast_nodes/generated/ast_nodes.rs'
+  - 'crates/oxc_formatter/src/ast_nodes/generated/format.rs'
   - 'crates/oxc_linter/src/generated/assert_layouts.rs'
   - 'crates/oxc_linter/src/lib.rs'
   - 'crates/oxc_regular_expression/src/ast.rs'