Fix error message for nonexistent vnf package

In Victoria release, the error handling of non-existing VNF package
was modified, please refer to [1].
On passing a non-existing vnf package uuid to "vnf package upload"
command, the tacker server sends an HTTP response with "Content-Type"
header as "application/problem+json" and the reason for a failure
described in the JSON problem details object.

This patch extracts the ETSI error message in method
exception_handler_v10.

Fixes the issue and now it will output below error message:

  $ openstack vnf package upload --path sample_vnf_pkg.zip dummy-id
  Can not find requested vnf package: dummy-id

Note: This bug was earlier address in Ussuri release, please refer [2].

[1] https://review.opendev.org/c/openstack/tacker/+/747678/37/tacker/api/vnfpkgm/v1/controller.py
[2] https://review.opendev.org/c/openstack/python-tackerclient/+/688886

Co-Authored-By: Wataru Juso  w-juso@nec.com
Closes-Bug: #1847726
Change-Id: I25e1bdc32e0b91bbe02b82f79918c02b98e5f110

tackerclient/v1_0/client.py

@@ -54,6 +54,7 @@ def exception_handler_v10(status_code, error_content):
     :param status_code: HTTP error status code
     :param error_content: deserialized body of error response
     """
+    etsi_error_content = error_content
     error_dict = None
     if isinstance(error_content, dict):
         error_dict = error_content.get('TackerError')
@@ -94,6 +95,12 @@ def exception_handler_v10(status_code, error_content):
         if message:
             raise exceptions.TackerClientException(status_code=status_code,
                                                    message=message)
+        # ETSI error response
+        if isinstance(etsi_error_content, dict):
+            if etsi_error_content.get('detail'):
+                message = etsi_error_content.get('detail')
+                raise exceptions.TackerClientException(status_code=status_code,
+                                                       message=message)
 
     # If we end up here the exception was not a tacker error
     msg = "%s-%s" % (status_code, error_content)