Make forms reusable

[shushugah]

Currently switching between different forms is very manual. Currently inside DeCapCMS you can set the boolean hide_form, but it should instead be the name of a form, and associated with that...it displays other kind of information, like accessibility for Zoom (as opposed to whatever physical venue)

and make it easier to reuse certain forms. currently the most common form is "subscribe" but "general" use could also be used...when bare minimum info is needed, while potluck is great for food centric events.