Adjustment for IP Trunk creation and modification. Added...

Did a couple of adjustment for IP Trunk creation and modification. Added default values for nullable fields.

gso/cli/imports.py

@@ -90,7 +90,7 @@ class IptrunkImportModel(BaseModel):
     partner: str
     geant_s_sid: str | None
     iptrunk_type: IptrunkType
-    iptrunk_description: str
+    iptrunk_description: str | None
     iptrunk_speed: PhysicalPortCapacity
     iptrunk_minimum_links: int
     iptrunk_isis_metric: int