Allow switch of camunda version just by changing the version property

So far, when you want to use a different version than the version the starter is compiled against, you have to provide a custom dependencyManagement-entry for the camunda-bom in the required version.

Other spring starters allow just to overwrite the used version by setting a new property.

We should evaluate how and if this is possible and provide a change.

Copied from https://github.com/camunda/camunda-bpm-spring-boot-starter/issues/257