(typescript): Fix invalid optional members and argument generation
(typescript): Fix invalid optional members and argument generation

Fixes two cases where the optional flag `?` is generated incorrectly for typescript, leading to invalid build:

 - Non-optional function arguments after optional arguments
 - Exception types with optional message

Jens-G/thrift,apache/thrift,nsuke/thrift,nsuke/thrift,apache/thrift,nsuke/thrift,apache/thrift,nsuke/thrift,Jens-G/thrift,apache/thrift,Jens-G/thrift,nsuke/thrift,apache/thrift,Jens-G/thrift,Jens-G/thrift,apache/thrift,Jens-G/thrift,Jens-G/thrift,nsuke/thrift,Jens-G/thrift,apache/thrift,apache/thrift,nsuke/thrift,nsuke/thrift,apache/thrift,nsuke/thrift,nsuke/thrift,Jens-G/thrift,nsuke/thrift,apache/thrift,Jens-G/thrift,nsuke/thrift,apache/thrift,apache/thrift,Jens-G/thrift,apache/thrift,Jens-G/thrift,Jens-G/thrift,apache/thrift,Jens-G/thrift,nsuke/thrift,apache/thrift,Jens-G/thrift,Jens-G/thrift,nsuke/thrift,nsuke/thrift,apache/thrift,nsuke/thrift,Jens-G/thrift,Jens-G/thrift,apache/thrift,nsuke/thrift,apache/thrift