Added New command (remove_template) to remove template in zabbix-cli.

[taybur43]

Hi Dear,

I am taybur Rahman, due to need of removing template using zabbix-cli, i have added a new method in zabbix-cli and rebuild the rpm. After that i have checked its working fine.
so let me know if you need that part of code or full rebuild rpm to verify and add with the main project.

Thanks

[paalbra]

Could you add this as a pull request?