[Test Framework] Add live tests for Test Proxy integration

[JoshLove-msft]

We should have "live" tests for the Test Framework that validate Test Proxy usage. We should exercise all of the different sanitization/matching options.

[pallavit]

@JoshLove-msft do we have any testing at all against the test proxy?

What scenarios do you have in mind here?

[pallavit]

@JoshLove-msft given we have migrated all our service test cases to test proxy - do you still see value in doing this? If anything were to be amiss we would be testing it through our service testcases.

[JoshLove-msft]

Agreed that there isn't much value in this at this point.