Remove custom sqlalchemy metadata, manage with __table_args__

Allow sqlmodel queries, with relations
Remode join_with mechanisms coming from gino
Handlew ith_only_columns in get_df and get_gdf
Implement feature-info

src/gisaf/models/misc.py

@@ -5,7 +5,7 @@ from pydantic import ConfigDict
 from sqlmodel import Field, JSON, Column
 
 from gisaf.models.models_base import Model
-from gisaf.models.metadata import gisaf_map
+from gisaf.models.metadata import gisaf_map_table_args
 
 logger = logging.getLogger(__name__)
 
@@ -19,7 +19,7 @@ class Qml(Model):
     Model for storing qml (QGis style)
     """
     model_config = ConfigDict(protected_namespaces=())
-    metadata = gisaf_map
+    __table_args__ = gisaf_map_table_args
 
     class Admin:
         menu = 'Other'