Add group fields to attribute types

[marktaipan-cvisionai]

Category Feature Request

Problem Groups of attributes aren't currently supported in entity types.

Request Support #1202 by adding a group name string field to the attribute type. There also should be some consideration to defining the group's order and style.

[bctcvai]

Does it make sense to describe groups in one spot (defining their order/style) ; and somehow reference them in each attribute?

[marktaipan-cvisionai]

I think so. Perhaps adding an attribute_type_groups to the entity types is the way to go. Then we can have order, style, name, and description at a minimum. Then for each attribute type, we can have a group field that would be the name.

[bctcvai]

This reads as a duplicate of: https://github.com/cvisionai/tator/issues/1202