Allow integrations to extend the UI fields of persons (or other integrations)

It would be great if integrations could extend the data you can add to other aspects of home assistant like the person integration

I think its best described with this example:
currently I use yaml config to extend the people in my home assistant with custom attributes like this:

homeassistant:
  customize:
    person.test:
      telegram_id: 0000000

this allows me to utilise the telegram_id in my notification automations (e.g. send a message via the telegram integration only to persons that are home or that are away)

To make this more accessible it would be great if integrations, like for example the telegram_bot integration could define “fields” (attributes) that should be added to certain “domains” or other integration like e.g. “person” (of course only if this other integration is “enabled”)
This could be (in this example) a text field in the UI when editing a person where you could input their telegram id to be used elsewhere (e.g. in automations)

I can imagine that other integrations might also have a use for this because they require some specific information that could be “attachable” to certain entities/integrations.