* improve import code fixes for UMD modules
- use default import under --allowSyntheticDefaultImports
- import..require support
- make make quick fix info match resulting import
- make diagnostics
* Address PR feedback:
- extract test for synethetic default imports into getAllowSyntheticDefaultImports in core.ts
- use getAllowSyntheticDefaultImports in checker.ts and importFixes.ts
- move compilerOptions to top level destructuring
* add tests
* remove `import =` quick fix and supporting code.
* update feature tests
* remove errant whitespace
