Extract inline type definitions of properties

What needs to be remodeled?

Inline type definitions. e.g.

  geo: {
    point: Point,
    polygon?: Polygon,
  }

How is the current model not sufficient?

As mentioned in core-tools#7 (comment 132312645) the inline type definitions cause great complexity for reading out their reflection-information.

Which changes are necessary?

Extract the inline type definitions into their own separate interface in the same file. No information will be lost or edited. This coding style should be added for the style guidelines, for developing new base/thing-types.

Do the proposed changes impact current use cases?

Would the proposed change affect creating instances of the types in any way? @krlwlfrt If not: None