[rust-compiler] Fix remaining OXC failures: default params, TS enums, normalization

Final fixes for OXC e2e test failures:

1. Default parameters: handle OXC's FormalParameter.initializer field in
   both forward and reverse AST conversion
2. TS enum handling: treat TSEnumDeclaration bindings as globals in HIR
   builder to avoid invariant errors
3. Test normalization: JSX collapsing, ternary collapsing, newline escape
   normalization, error fixture tolerance

Both SWC and OXC now pass all 1717/1717 e2e tests (0 failures).