Client plugin exception handling methods

This change adds common methods which allow resources
to handle client exceptions without needing to directly
import the exception types.

The most common client resource exception handling is:
* Detecting if an exception is a 404
* Raising any exception which is not a 404
* Detecting if an exception is a 413 (over limit)
* Detecting if an exception was raised by a particular client
  library

Subsequent changes will move to using these methods.

Change-Id: Ib2bd55c31e66b562cfa8388beb450be6c06cc4fb
Merge "Client plugin exception handling methods"