Sediment: Add solid BC, QSO export and profile + point sediment layers export.

src/Model/BoundaryCondition/BoundaryCondition.py

@@ -83,7 +83,8 @@ class BoundaryCondition(SQLSubModel):
     def _get_ctor_from_type(cls, t):
         from Model.BoundaryCondition.BoundaryConditionTypes import (
             NotDefined, PonctualContribution,
-            TimeOverZ, TimeOverDischarge, ZOverDischarge
+            TimeOverZ, TimeOverDischarge, ZOverDischarge,
+            Solid,
         )
 
         res = NotDefined
@@ -95,6 +96,8 @@ class BoundaryCondition(SQLSubModel):
             res = TimeOverDischarge
         elif t == "ZD":
             res = ZOverDischarge
+        elif t == "SL":
+            res = Solid
         return res
 
     @classmethod