fix(model): Fix States.functions

The definition of `capellacommon.States.functions` was using the
`AbstractFunction` base class to attempt to capture all possible
subclasses, which is not currently supported. Also, it was wrongly using
camelCase instead of snake_case for the lookup attribute.

Fixes #358

capellambse/model/__init__.py

@@ -640,3 +640,19 @@ def _reference_attributes(objtype: type[ModelObject], /) -> tuple[str, ...]:
         ):
             attrs.append(i)
     return tuple(attrs)
+
+
+common.set_accessor(
+    capellacommon.State,
+    "functions",
+    common.ReferenceSearchingAccessor(
+        (
+            oa.OperationalActivity,
+            ctx.SystemFunction,
+            la.LogicalFunction,
+            pa.PhysicalFunction,
+        ),
+        "available_in_states",
+        aslist=common.ElementList,
+    ),
+)

capellambse/model/crosslayer/capellacommon.py

@@ -28,8 +28,6 @@ class AbstractStateMode(c.GenericElement):
 
     regions = c.DirectProxyAccessor(Region, aslist=c.ElementList)
 
-    functions: c.Accessor
-
 
 @c.xtype_handler(None)
 class State(AbstractStateMode):
@@ -45,6 +43,8 @@ class State(AbstractStateMode):
         c.GenericElement, "exit", aslist=c.MixedElementList
     )
 
+    functions: c.Accessor
+
 
 @c.xtype_handler(None)
 class Mode(AbstractStateMode):

capellambse/model/crosslayer/fa.py

@@ -396,16 +396,6 @@ def __dir__(self) -> list[str]:
     ),
 )
 
-c.set_accessor(
-    capellacommon.State,
-    "functions",
-    c.ReferenceSearchingAccessor(
-        AbstractFunction,
-        "availableInStates",
-        aslist=c.ElementList,
-    ),
-)
-
 c.set_accessor(
     Function,
     "exchanges",