Be able to set Camunda 8 version in process application

[philippfromme]

Problem you would like to solve

Camunda 8 versions are currently set individually for each BPMN diagram, DMN diagram and Camunda Form. Since a process application is going to deployed as a whole a single Camunda 8 version should be set for all resources in that process application.

Proposed solution

• set Camunda 8 version for all resources in a process application

Alternatives considered

None.

Additional context

Related to #2508

[philippfromme]

This is not working in the Web Modeler currently: https://github.com/camunda/web-modeler/issues/11676