Replace deprecated python 3.8 code and add missing __init__.py files for proper python module recognition

Author: ksuszka

srunner/osc2/ast_manager/__init__ .py srunner/osc2/__init__.py

@@ -80,7 +80,7 @@ def parse_routes_file(route_filename, single_route_id=''):
                 scenario_config.name = scenario.attrib.get('name')
                 scenario_config.type = scenario.attrib.get('type')
 
-                for elem in scenario.getchildren():
+                for elem in list(scenario):
                     if elem.tag == 'trigger_point':
                         scenario_config.trigger_points.append(convert_elem_to_transform(elem))
                     elif elem.tag == 'other_actor':

srunner/osc2/ast_manager/__init__.py

@@ -68,7 +68,7 @@ def parse_scenario_configuration(scenario_name, additional_config_file_name):
                 config.name = scenario_config_name
                 config.type = scenario_config_type
 
-                for elem in scenario.getchildren():
+                for elem in list(scenario):
                     # Elements with special parsing
                     if elem.tag == 'ego_vehicle':
                         config.ego_vehicles.append(ActorConfigurationData.parse_from_node(elem, 'hero'))