This reverts commit f45f925e5e1dbfec627345868d0dd56abc77c4f1, reversing
changes made to 90c07943e4173ef8e32dae5087203f5a712f8077.
This was too early, need to check for incubator
Apply for rules are defined through `apply_for` property
Only Array custom variables will be eligible in apply_for dropdown.
API Example:
```bash
./director-curl POST director/service?name=my_service '{"apply_for": "for (checked_tcp_port in host.vars.checked_tcp_ports)" }'
```
Will render as:
```
apply Service "my_service" for (checked_tcp_port in host.vars.checked_tcp_ports) {
...
}
```
Feature: https://dev.icinga.org/issues/11976
Depends-On: https://github.com/Icinga/icingaweb2-module-director/pull/20
refs #11976
