fix: remove action feature flag and include execution (#9727)

# Which Problems Are Solved

Actions v2 is not a feature flag anymore, include functionality on
executions is not used and json tags of proto messages are handled
incorrectly.

# How the Problems Are Solved

- Remove actions from the feature flags on system and instance level
- Remove include type on executions, only in the API, later maybe in the
handling logic as well
- Use protojson in request and response handling of actions v2

# Additional Changes

- Correct integration tests for request and response handling
- Use json.RawMessage for events, so that the event payload is not
base64 encoded
- Added separate context for async webhook calls, that executions are
not cancelled when called async

# Additional Context

Related to #9759 
Closes #9710

---------

Co-authored-by: Livio Spring <livio.a@gmail.com>

internal/command/instance_features_test.go

@@ -149,24 +149,6 @@ func TestCommands_SetInstanceFeatures(t *testing.T) {
 				ResourceOwner: "instance1",
 			},
 		},
-		{
-			name: "set Actions",
-			eventstore: expectEventstore(
-				expectFilter(),
-				expectPush(
-					feature_v2.NewSetEvent[bool](
-						ctx, aggregate,
-						feature_v2.InstanceActionsEventType, true,
-					),
-				),
-			),
-			args: args{ctx, &InstanceFeatures{
-				Actions: gu.Ptr(true),
-			}},
-			want: &domain.ObjectDetails{
-				ResourceOwner: "instance1",
-			},
-		},
 		{
 			name: "push error",
 			eventstore: expectEventstore(
@@ -204,10 +186,6 @@ func TestCommands_SetInstanceFeatures(t *testing.T) {
 						ctx, aggregate,
 						feature_v2.InstanceUserSchemaEventType, true,
 					),
-					feature_v2.NewSetEvent[bool](
-						ctx, aggregate,
-						feature_v2.InstanceActionsEventType, true,
-					),
 					feature_v2.NewSetEvent[bool](
 						ctx, aggregate,
 						feature_v2.InstanceOIDCSingleV1SessionTerminationEventType, true,
@@ -219,7 +197,6 @@ func TestCommands_SetInstanceFeatures(t *testing.T) {
 				TriggerIntrospectionProjections: gu.Ptr(false),
 				LegacyIntrospection:             gu.Ptr(true),
 				UserSchema:                      gu.Ptr(true),
-				Actions:                         gu.Ptr(true),
 				OIDCSingleV1SessionTermination:  gu.Ptr(true),
 			}},
 			want: &domain.ObjectDetails{