Implement Zabbix support

[stdevel]

Is your feature request related to a problem? Please describe. It would be great to have Zabbix support.

Describe the solution you'd like The Zabbix support should include the core functions used in katprep:

• retrieving host/IP information
• retrieving monitoring status
• scheduling/removing downtimes

Describe alternatives you've considered

Additional context There is a documented API: https://www.zabbix.com/documentation/current/manual/api

[stdevel]

Some TODOs:

• [ ] implement ZabbixAPIClient.py
• [ ] implement unit tests and cookbook for creating Zabbix vagrant boxes