Add actions from schema.org as GMail supports them

Feature Request

Are there any plans for supporting schema.org actions like those that GMail is supports? Or is there anything that would block adding support for them?

If not, I would like to investigate in this topic and maybe add the support. Maybe not for all kinds of actions at once, but stepwise – first only the easy ones (the basic ones) and maybe the more complex later.

There might also be an option to accept or deny event requests, and adding the related event to the personal calendar at NextCloud if accepted (or do we have this already? I am not sure about this).

Extract from the linked document

Gmail supports the following types of actions and interactive cards:

• One-click Action for just about anything that can be performed with a single click
• Go-to Action for more complex interactions
• Flight interactive cards

Gmail uses the same schema.org markup to highlight the most important information within an email, and allow user to act on it.

• Bus Highlight
• Car Rental Highlight
• Flight Highlight
• Event Highlight for events with tickets
• Order and parcel delivery Highlights for shopping
• Hotel Highlight for hotel reservations
• Invoice Highlight
• Restaurant Highlight for restaurant reservations
• Train Highlight

Start with the linked Gmail markup overview and compare its schema.org actions and highlights with the current mail app capabilities. Define a focused first subset, including whether event requests and Nextcloud calendar integration are in scope; done means that subset and its behavior are agreed and supported.