More automated remove fabric mechanism

[cecille]

We have a lot of tests where the last step of the test is to remove the extra fabrics added in the test.

There are also a lot of tests where this isn't done.

It would make sense to have the test framework remove extra fabrics as part of the test teardown. The function would have to be careful to only remove fabrics added as a part of the test - ie, fabrics that are listed in the test framework certificate authority manager.