fix: ticker events returns composite_figi

[shooit]

fixes #422

[shooit]

Here's the interactive docs showing the expected response shape:

[justinpolygon]

LGTM - this fixes an issue where the client library was throwing an error when getting ticket events.

Before:

Traceback (most recent call last):
  File "/Users/jw/work/client-python/examples/rest/stocks-ticker_events.py", line 11, in <module>
    print(events)
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.9/lib/python3.9/dataclasses.py", line 370, in wrapper
    result = user_function(self)
  File "<string>", line 3, in __repr__
AttributeError: 'TickerChangeResults' object has no attribute 'figi'

After:

TickerChangeResults(name='Meta Platforms, Inc. Class A Common Stock', composite_figi='BBG000MM2P62', cik='0001326801', events=[{'ticker_change': {'ticker': 'META'}, 'type': 'ticker_change', 'date': '2022-06-09'}, {'ticker_change': {'ticker': 'FB'}, 'type': 'ticker_change', 'date': '2012-05-18'}])

[justinpolygon]

LGTM