This commit updates TypeScript and other dependencies used in angular.io
to more closely align with new apps created with the latest Angular CLI.
It also updates `tsconfig.json`, re-ordering some properties around and
introducing some more checks (again to more closely match new CLI apps).
NOTE:
I skipped updating RxJS from 6.5.4 to 6.6.3, because it increased the
main bundle by ~500B.
NOTE:
`tslint.json` will be updated in a subsequent PR, because it requires
more extensive changes.
PR Close#39017
0d238aa9d9