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/api/grpc/action/v2beta/server.go

@@ -1,8 +1,6 @@
 package action
 
 import (
-	"context"
-
 	"google.golang.org/grpc"
 
 	"github.com/zitadel/zitadel/internal/api/authz"
@@ -10,7 +8,6 @@ import (
 	"github.com/zitadel/zitadel/internal/command"
 	"github.com/zitadel/zitadel/internal/config/systemdefaults"
 	"github.com/zitadel/zitadel/internal/query"
-	"github.com/zitadel/zitadel/internal/zerrors"
 	action "github.com/zitadel/zitadel/pkg/grpc/action/v2beta"
 )
 
@@ -65,10 +62,3 @@ func (s *Server) AuthMethods() authz.MethodMapping {
 func (s *Server) RegisterGateway() server.RegisterGatewayFunc {
 	return action.RegisterActionServiceHandler
 }
-
-func checkActionsEnabled(ctx context.Context) error {
-	if authz.GetInstance(ctx).Features().Actions {
-		return nil
-	}
-	return zerrors.ThrowPreconditionFailed(nil, "ACTION-8o6pvqfjhs", "Errors.Action.NotEnabled")
-}