Add new types into db table.
Extending the existing API, including Listener, Pool, HealthMonitor for
UDP fields support.
For healthmonitor part, need to wait for other patch to fix the default
value.
Patch List:
[1] Finish keepalived LVS jinja template for UDP support
[2] Extend the ability of amp agent for upload/refresh the keepalived
process
[3] Extend the db model and db table with necessary fields for met the new
udp backend
[4] Add logic/workflow elements process in UDP cases
[5] Extend the existing API to access udp parameters in Listener API
[6] Extend the existing pool API to access the new option in
session_persistence fields
Story: 1657091
Task: 5484
Change-Id: If728705f142f4195fe624bd9ef17413722d54fe3
4c6846a568