Add missing pagination support to References Clients

[ryangribble]

Refer #1659

Implement Pagination on the following clients

IReferencesClient and IObservableReferencesClient

• GetAll(string owner, string name)
• GetAll(long repositoryId)
• GetAllForSubNamespace(string owner, string name, string subNamespace)
• GetAllForSubNamespace(long repositoryId, string subNamespace)

Checklist

• Remove convention test exclusion

• Add ApiOptions overload

  • make existing methods call new overload with ApiOptions.None

• Update unit tests

  • Adjust for ApiOptions parameter
  • Add null check for ApiOptions

• Add pagination Integration tests

  • ReturnsCorrectCountOfXWithoutStart
  • ReturnsCorrectCountOfXWithStart
  • ReturnsDistinctXBasedOnStartPage