Make component overrides easily re-usable

This suggestion adds a new twist to the paradigm of "configuration paragraphs": we already use similar approach for the "Automated list", where the configuration of what would be displayed is passed down the processing pipeline to the view.

I like this suggestion from the point of re-usability of settings between content types: if a new content type wants to use Banner overrides - adding a "Banner override" paragraph should provide such functionality in an easy way with all the "wiring" already in-place.

The scope of the implementation needs to be widen to include possible future overrides for other components added within CivicTheme or in a consumer site.

The paragraph for a specific component can be collapsed or expanded by OOTB CivicTheme based on the component itself to make it more apparent for the content editor what the override fields are, which will make the Banner Overrides UI looking to closer to what it is now than what it is on the screenshot in the description.

This will also require an update hook to migrate existing site to use such configuration paragraphs.

@sime
Thank you for your suggestion. This is solid.

Thanks for the suggestions. We probably won't be doing anything on this at this stage in the V1 project but will leave open in postponed if we look into the architecture etc.