ComplianceChecker issues

[dgovil]

I just wanted to report a few issues we hit in the complianceChecker code base with USD 21.11

1. Some of the tests reference AddFailedCheck instead of _AddFailedCheck and fail due to the missing attribute
   https:/PixarAnimationStudios/USD/blob/faed18ce62c8736b02413635b584a2f637156bad/pxr/usd/usdUtils/complianceChecker.py#L417

2. The UsdShade::ConnectableAPI fails when it encounters a prim type that ti doesn't know about. This causes it to fail running the tests rather than just being surfaced as an error when an unknown prim is encountered. This happens in the C++ layer and doesn't seem to get bubbled up properly.

#usda 1.0

def Foo "MyPrim" () {}

[spiffmon]

Thank you , @dgovil ! Problem #1 is fixed in 22.03. I remember also fixing a problem with the ConnectableAPIBehavior registry, but don't recall if that was it, specifically.

[dgovil]

Awesome, thanks, Spiff!

[jilliene]

Filed as internal issue #USD-7180