#27253 Fixes regression in 0.15 with cloned pipeline configuration init

In 0.15.x, the pipeline configuration data is cached in a new way, eliminating the need for one of the lookup files in the project storage location. There was however, a regression, caused by the fact that the cache was not refreshed from Shotgun unless there was a full cache miss - e.g. the entire project was missing from the pipeline configuration. If there was a primary config present for a project in the cache, the cache was deemed as being valid. This meant that if someone cloned the primary config, the data about the clone would not appear in the cache and toolkit would think that the clone location was not a valid pipeline configuration.

This change fixes this issue by adding a higher-level try/catch, making it more consistent with the behaviour in the `sgtk.from_entity()` method.
It seemed simpler to just go with TankError. The majority (if not all) of the TankErrors raised in here would be as a consequence of cache misses and if I used some other exception I guess I have to "re-dress" the exception back to be a TankError before passing it out into the outer world. Hope you are okay with that reasoning!