Align optional parameters for span related to exceptions, add exception.escaped for record_exception

[lzchen]

start_as_current_span() and start_span() should have identical constructors. For the parameters related to exception and status:

1. record_exception - whether or not to automatically call record_exception() if exception raised
2. set_status_on_exception - whether or not to automatically set span status to ERROR if exception raised

As well, from this comment,
adding exception.escaped attribute when exception raised from span being used as a context manager.

[aabmass]

Would it work if on line 854 if you did

with span:
    yield span

to avoid repeating this code?

[lzchen]

This would work. The only reason why I left it in two different places is because record_exception wouldn't know if escaped is True or not.

[ocelotl]

Just a nit.