Upgraded @jangaroo/ext-ts to 2.1.0

@jangaroo/ext-ts was upgraded to 2.1.0. This fixes problems with incorrectly typed component event signatures and also allows using the aforementioned package in a typescript project with strict mode without running into unexpected errors.

Follow Section, “Upgraded @jangaroo/ext-ts to 2.1.0” for upgrade information.

(CMS-27671)