FR: Ability to filter/exclude Users in a User Field

[binoclard]

It would be really useful imho to be able to define if a User gets to be displayed in a User Field, either at the User level, or the Role/Group level.

For example, I would like to exclude my own User as super-admin, I do not need it to appear in a author Field. Or slim down the list to only a selection, that could differ from a Collection to another, etc.

Maybe defining in the Fieldset what groups the Field should fetch and display?