Add possibility to use MySQL backend

Just for the information:
The base code for row_present state was mainly taken from sqlite3
SaltStack state.

MySQL database schema was taken from:
https://doc.powerdns.com/authoritative/backends/generic-mysql.html

Related-PROD: PROD-21596 (PROD:21596)

Change-Id: If58216b058c352c692ea4997019193dba287038a
8 files changed