Type extension mechanism

[rcasteran]

Is your feature request related to a problem? Please describe. Add mechanism to allow to derive new types from the created ones

Describe the solution you'd like

• Support the extension between types through the following command:

  <type 1 name> extends <type 2 name>

Extension mechanism must ensure that the same rules/commands that are relevant for type 2 are relevant for type 1

Describe alternatives you've considered None