fix(properties-panel): require explicit declaration of properties providers
fix(properties-panel): require explicit declaration of properties providers

Reverts previous change.

BREAKING CHANGE:

* You have to choose a properties provider yourself and pass
it to bpmn-js via a module together with the properties panel

aakhmerov/bpmn-js-properties-panel,bpmn-io/bpmn-js-properties-panel,bpmn-io/bpmn-js-properties-panel