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/settings/object/v3alpha/converter.go

@@ -0,0 +1,20 @@
+package object
+
+import (
+	"google.golang.org/protobuf/types/known/timestamppb"
+
+	"github.com/zitadel/zitadel/internal/domain"
+	object "github.com/zitadel/zitadel/pkg/grpc/object/v3alpha"
+	settings_object "github.com/zitadel/zitadel/pkg/grpc/settings/object/v3alpha"
+)
+
+func DomainToDetailsPb(objectDetail *domain.ObjectDetails, owner *object.Owner) *settings_object.Details {
+	details := &settings_object.Details{
+		Sequence: objectDetail.Sequence,
+		Owner:    owner,
+	}
+	if !objectDetail.EventDate.IsZero() {
+		details.ChangeDate = timestamppb.New(objectDetail.EventDate)
+	}
+	return details
+}