[Sirius][ProfileDiagram] Extension link should only work with Metaclass

Bugzilla Link	581937
Status	NEW
Importance	P3 normal
Reported	May 12, 2023 09:23 EDT
Modified	May 12, 2023 09:23 EDT
Version	0.7.0

Description

On the current Papyrus-Sirius Profile diagram version, the extension link can be created from a Stereotype to a Class. This behavior must be forbidden.
Requirements to implement:

1. An Extension can only be created from a Stereotype to a Metaclass
2. An Extension can only be retargeted (target side) from a Metaclass to another Metaclass.