Copy the attributes from one existing feature to another

[m-kuhn]

What I would also find great would be the possibility to just copy the attributes from one existing feature to another.

1. add a new button to "copy attributes" of a selected feature (should only appear if exactly one feature is selected)
2. from now on the button to "paste attribute" appears next to it (this button is also visible if multiple features are selected at the same time, to apply the copied attributes to all selected features)
3. the crowning glory would be, if the copying also works cascaded including possible existing relations and ...
4. ... there would be the possibility to mark/ exclude attributes to be copied. Maybe by a checkbox similar to the one you already use to mark attribute entries for the next feature.

Originally posted by @lp-dj in https://github.com/opengisch/QField/issues/1825#issuecomment-900391572