fix(errors): [2/2] Rename Exception to Error; remove from public API

BREAKING CHANGE:

Exceptions are no longer part of the public API. We don't expect that anyone should be referring to the Exception types.

ExceptionHandler.call(exception: any, stackTrace?: any, reason?: string): void;
change to:
ErrorHandler.handleError(error: any): void;

modules/playground/e2e_test/sourcemap/sourcemap_spec.ts

@@ -52,7 +52,7 @@ describe('sourcemaps', function() {
                                 encoding: 'UTF-8'
                               }).split('\n');
       expect(sourceCodeLines[originalPosition.line - 1])
-          .toMatch(/throw new BaseException\(\'Sourcemap test\'\)/);
+          .toMatch(/throw new Error\(\'Sourcemap test\'\)/);
     });
   });
 });