v1.28.1

Improvements

• Adjust the generation of the $filter parameter in URL so that parentheses are not removed even logically they are not needed.
  For example, now $filter=((filterA and filter B) and (filterC and filter D)) will not be flattened to $filter=(filterA and filter B and filterC and filter D).

Fixed Issues

• [Generator] Remove Batch.ts from the index file when the file does not exist.