feat(v3alpha): write actions (#8225)

# Which Problems Are Solved

The current v3alpha actions APIs don't exactly adhere to the [new
resources API
design](https://zitadel.com/docs/apis/v3#standard-resources).

# How the Problems Are Solved

- **Breaking**: The current v3alpha actions APIs are removed. This is
breaking.
- **Resource Namespace**: New v3alpha actions APIs for targets and
executions are added under the namespace /resources.
- **Feature Flag**: New v3alpha actions APIs still have to be activated
using the actions feature flag
- **Reduced Executions Overhead**: Executions are managed similar to
settings according to the new API design: an empty list of targets
basically makes an execution a Noop. So a single method, SetExecution is
enough to cover all use cases. Noop executions are not returned in
future search requests.
- **Compatibility**: The executions created with previous v3alpha APIs
are still available to be managed with the new executions API.

# Additional Changes

- Removed integration tests which test executions but rely on readable
targets. They are added again with #8169

# Additional Context

Closes #8168

internal/api/grpc/resources/action/v3alpha/server.go

@@ -0,0 +1,70 @@
+package action
+
+import (
+	"context"
+
+	"google.golang.org/grpc"
+
+	"github.com/zitadel/zitadel/internal/api/authz"
+	"github.com/zitadel/zitadel/internal/api/grpc/server"
+	"github.com/zitadel/zitadel/internal/command"
+	"github.com/zitadel/zitadel/internal/query"
+	"github.com/zitadel/zitadel/internal/zerrors"
+	action "github.com/zitadel/zitadel/pkg/grpc/resources/action/v3alpha"
+)
+
+var _ action.ZITADELActionsServer = (*Server)(nil)
+
+type Server struct {
+	action.UnimplementedZITADELActionsServer
+	command             *command.Commands
+	query               *query.Queries
+	ListActionFunctions func() []string
+	ListGRPCMethods     func() []string
+	ListGRPCServices    func() []string
+}
+
+type Config struct{}
+
+func CreateServer(
+	command *command.Commands,
+	query *query.Queries,
+	listActionFunctions func() []string,
+	listGRPCMethods func() []string,
+	listGRPCServices func() []string,
+) *Server {
+	return &Server{
+		command:             command,
+		query:               query,
+		ListActionFunctions: listActionFunctions,
+		ListGRPCMethods:     listGRPCMethods,
+		ListGRPCServices:    listGRPCServices,
+	}
+}
+
+func (s *Server) RegisterServer(grpcServer *grpc.Server) {
+	action.RegisterZITADELActionsServer(grpcServer, s)
+}
+
+func (s *Server) AppName() string {
+	return action.ZITADELActions_ServiceDesc.ServiceName
+}
+
+func (s *Server) MethodPrefix() string {
+	return action.ZITADELActions_ServiceDesc.ServiceName
+}
+
+func (s *Server) AuthMethods() authz.MethodMapping {
+	return action.ZITADELActions_AuthMethods
+}
+
+func (s *Server) RegisterGateway() server.RegisterGatewayFunc {
+	return action.RegisterZITADELActionsHandler
+}
+
+func checkExecutionEnabled(ctx context.Context) error {
+	if authz.GetInstance(ctx).Features().Actions {
+		return nil
+	}
+	return zerrors.ThrowPreconditionFailed(nil, "ACTION-8o6pvqfjhs", "Errors.Action.NotEnabled")
+}