This patch implements retry operation task defined in ETSI NFV-SOL003
v3.3.1 5.4.14.
Basically retry operation is not task API specific. Thus retry
operation of a task API which is added in the future (ex. scale)
will be supported naturally.
Functional tests will be provided with another patch.
Implements: blueprint support-nfv-solv3-error-handling
Change-Id: I2717540f042882363cce3d1a0da22c71789a36cb