Clean up QuicStreamIdManagerTests
* Parameterize the test on perspective in addition to
  directionality to make sure all tests cover all
  configurations
* Replace Client/Server/Base Test classes with a single class
* Remove confusing StreamCountToId method
* Replace 3 GetNth<Bidi|Uni><Client|Server> methods with a
  single GetNthIncomingStreamId method.
* Remove redundant tests.
* Rename IsUni to IsUnidirectional to comply with the style guide
  and remove IsBidi.
* Rename various tests to remove redundancy in the names
* Remove some redundant comments.

gfe-relnote: n/a - Test and DCHECK only
PiperOrigin-RevId: 270351085
Change-Id: I63f705ecbf8c36b123c3b8976d55204ada4e8ac2