Fix `ProblemDetails.detail` from `.details`
Fix `ProblemDetails.detail` from `.details`

Field name `details` is used in ProblemDetails Object, but
it should be `detail`. This field missmatch cause
NotImplemntError when failing to instantiate VNF.

This patch fixes the filed 'details' to 'detail' in
ProblemDetails Object.

Closes-Bug: 1905680
Change-Id: I71b333dc05f2195dacb478f3f0bc442dac9c5691

stackforge/tacker,openstack/tacker,stackforge/tacker,openstack/tacker,openstack/tacker