Consider adding an implementation of an addModule helper

[Skaiir]

Context

Often when I go around looking at plugin implementation I find large helper functions with end up being re-implemented everywhere, These are used when adding modules to bpmn or dmn during an event subscription and looks like this: https://github.com/FlowSquad/camunda-modeler-i18n-plugin/blob/6a526ea4c43e648cc943439cf7accb54dd559d85/client/config/I18nPlugin.js#L119

What we should do

Add these helper functions here and save people some time and lines of code re-implementing them every time they want to build a plugin.