Allow testCase.update method to set tags for a test case.

[kj-brown]

Is your feature request related to a problem? Please describe.
We use tags to set our test cases to a particular squad - however, if we want to switch functionality to a new squad the API has to find and add/remove each tag one by one. This is slow, labourious, and infuriating.

Describe the solution you'd like
The ability to set the tags for a given test case, as part of the testCase.update api call. setting a tags property would allow us to improve the experience and update the case at the same time we sync.