Add QuotaError handling to servers rebuild API

Commit 718a3f057cee0b1163c40fbcbedda29bd2ef9dfe made
nova.compute.api.API._check_injected_file_quota raise more specific
over-quota exceptions but the rebuild API was never updated to handle
the QuotaError exceptions and translate to a proper HTTP error.

This change does a few things:

1. Makes the specific file path/content limit exceeded exceptions
   extend the more generic OnsetFileLimitExceeded exception.

2. Adds the OverQuota checking to the rebuild APIs with tests.

3. Adds unit tests for the three different exceptions raised from
   _check_injected_file_quota in the compute API since those did not
   exist before.

Closes-Bug: #1358380

Change-Id: I9c72dea6075fcf554abb8e669cf4dd3129176912
Merge "Add QuotaError handling to servers rebuild API"