Support HOT according to the ETSI-NFV SOL014

This blueprint enhances the Tacker’s supported parameters mapped to the OpenStack's Heat Orchestration Template (HOT) [1]. Though Tacker has already been implemented LCM operations using HOT [2], its supported parameters were limited. The further support of the parameters in HOT with ETSI-NFV SOL014 [3] makes Tacker more flexible and powerful as Generic-VNFM.

[1] https://docs.openstack.org/heat/latest/template_guide/openstack.html
[2] https://specs.openstack.org/openstack/tacker-specs/specs/ussuri/lcm-operation-with-lcm-operation-user-data.html
[3] https://www.etsi.org/deliver/etsi_gs/NFV-SOL/001_099/014/