Add utype as field on BaseObject

Since utype can be assigned to schemas, tables, columns, and foreign
keys in TAP_SCHEMA, it makes sense to have utype as a field on the
base Pydantic object rather than just on column.

python/felis/datamodel.py

@@ -89,6 +89,9 @@ class BaseObject(BaseModel):
     `BaseObject.Config.require_description` is set to `True` by the user.
     """
 
+    votable_utype: str | None = Field(None, alias="votable:utype")
+    """The VOTable utype (usage-specific or unique type) of the object."""
+
     @model_validator(mode="before")
     @classmethod
     def check_description(cls, values: dict[str, Any]) -> dict[str, Any]:
@@ -171,9 +174,6 @@ class Column(BaseObject):
     """TAP_SCHEMA indication that this column is defined by an IVOA standard.
     """
 
-    votable_utype: str | None = Field(None, alias="votable:utype")
-    """The VOTable utype (usage-specific or unique type) of the column."""
-
     votable_xtype: str | None = Field(None, alias="votable:xtype")
     """The VOTable xtype (extended type) of the column."""
 

python/felis/tap.py

@@ -180,7 +180,7 @@ def visit_schema(self, schema_obj: Schema) -> None:
 
         schema.schema_name = self._schema_name()
         schema.description = schema_obj.description
-        schema.utype = None  # FIXME: Hard-coded to None
+        schema.utype = schema_obj.votable_utype
         schema.schema_index = schema_obj.tap_schema_index
 
         if self.engine is not None:
@@ -238,7 +238,7 @@ def visit_table(self, table_obj: Table, schema_obj: Schema) -> tuple:
         table.schema_name = self._schema_name()
         table.table_name = self._table_name(table_obj.name)
         table.table_type = "table"
-        table.utype = None  # FIXME: Hard-coded table utype to None
+        table.utype = table_obj.votable_utype
         table.description = table_obj.description
         table.table_index = table_obj.tap_table_index
 
@@ -332,7 +332,7 @@ def visit_constraint(self, constraint_obj: Constraint) -> tuple:
         if constraint_type == "ForeignKey":
             constraint_name = constraint_obj.name
             description = constraint_obj.description
-            utype = None  # FIXME: Hard-coded constraint utype to None
+            utype = constraint_obj.votable_utype
 
             columns = [self.graph_index[col_id] for col_id in getattr(constraint_obj, "columns", [])]
             refcolumns = [