Default callout template

[SimoneZaza]

Description

As a Space admin, I would like the ability to set a default template for new callouts.

Acceptance criteria

• Give the option to choose a callout template from the space library to set as default for all callouts in a space. Note that this is just a template, so when creating a callout, people can actually change it completely, but it gives a clear hint of what is expected.

Additional Context

Screen shots / UX designs / data that are relevant.

Areas that will be affected

To be added during the refinement