Add support for pipeline templates

[dominikriemer]

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As we have an increasing number of pipeline elements which users can use in the pipeline editor, it becomes more complex to find appropriate pipeline elements for a specific task.
To ease the creation of pipelines, we can introduce Pipeline Templates, which can be stored in the database and reused in the pipeline editor. Templates consist of a combination of data processors and sinks and can be connected to available streams.
We can also use the new template concept to improve the creation of the Persist pipeline in the adapter creation view.

StreamPipes Committer

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