WordPress app can't be added to env if ZabbixAgent isn't uploaded

[Anastasia Kuznetsova]

Steps to reproduce:
1. Create *.zip archive with WordPress (I used version from murano-apps)
2. Import this package to Murano
3. Create Murano environment
4. Try to add WordPress application to just created env

Observed result:
Error: Application with FQN='io.murano.apps.ZabbixAgent' doesn't exist and user can't add WordPress app to his env, while ZabbixAgant is optional for WordPress

[Dmytro Dovbii (ddovbii)]

The fixing of this error lies in disabling validation of contracts. This seriously affects the integrity of building applications architecture and causes problems with applications that can be inherited from the Zabbix agent.
In real life, the user himself does't load applications to catalog. So, the current error message is enough to understand the operator what to do.
In the future, this problem will be partially or completely solved by Requirements

[Stan Lagun (slagun)]

Zabbix package is required by WordPress even if you not enter in the form because application need to work for any valid input. So the package need to be uploaded and this will be validated once we have requirements. It will also be required for a form to work correctly because we will need to find all ZabbixAgent inheritors present in environment and this cannot be done without knowing what ZabbixAgent is. Thus this is not a bug by design