Add E2E Workflow Tests in .NET SDK

[WhitWaldo]

Back when the Workflow functionality was included in Dapr.Client, an E2E test was created that performed a series of workflow activities and validated that the logging output correctly reflected the behaviors.

As #1345 removes the obsolete methods from Dapr.Client, these E2E tests were removed.

By the time 1.16 is released, I propose that we look at both adding E2E tests and identify/resolve opportunities to improve the unit test coverage specifically for the Dapr.Workflow project.

[WhitWaldo]

This is being tackled as a continued effort spanning several PRs:
#1662
#1664
#1669
#1671
#1672