feat: add debug events API (#8533)

# Which Problems Are Solved

Add a debug API which allows pushing a set of events to be reduced in a
dedicated projection.
The events can carry a sleep duration which simulates a slow query
during projection handling.

# How the Problems Are Solved

- `CreateDebugEvents` allows pushing multiple events which simulate the
lifecycle of a resource. Each event has a `projectionSleep` field, which
issues a `pg_sleep()` statement query in the projection handler :
  - Add
  - Change
  - Remove
- `ListDebugEventsStates` list the current state of the projection,
optionally with a Trigger
- `GetDebugEventsStateByID` get the current state of the aggregate ID in
the projection, optionally with a Trigger


# Additional Changes

- none

# Additional Context

-  Allows reproduction of https://github.com/zitadel/zitadel/issues/8517

internal/command/debug_events_model.go

@@ -0,0 +1,68 @@
+package command
+
+import (
+	"github.com/zitadel/zitadel/internal/domain"
+	"github.com/zitadel/zitadel/internal/eventstore"
+	debug "github.com/zitadel/zitadel/internal/repository/debug_events"
+)
+
+type DebugEventsWriteModel struct {
+	eventstore.WriteModel
+	State domain.DebugEventsState
+	Blob  string
+}
+
+func NewDebugEventsWriteModel(aggregateID, resourceOwner string) *DebugEventsWriteModel {
+	return &DebugEventsWriteModel{
+		WriteModel: eventstore.WriteModel{
+			AggregateID:   aggregateID,
+			ResourceOwner: resourceOwner,
+		},
+	}
+}
+
+func (wm *DebugEventsWriteModel) AppendEvents(events ...eventstore.Event) {
+	wm.WriteModel.AppendEvents(events...)
+}
+
+func (wm *DebugEventsWriteModel) Reduce() error {
+	for _, event := range wm.Events {
+		wm.reduceEvent(event)
+	}
+	return wm.WriteModel.Reduce()
+}
+
+func (wm *DebugEventsWriteModel) reduceEvent(event eventstore.Event) {
+	if event.Aggregate().ID != wm.AggregateID {
+		return
+	}
+	switch e := event.(type) {
+	case *debug.AddedEvent:
+		wm.State = domain.DebugEventsStateInitial
+		if e.Blob != nil {
+			wm.Blob = *e.Blob
+		}
+	case *debug.ChangedEvent:
+		wm.State = domain.DebugEventsStateChanged
+		if e.Blob != nil {
+			wm.Blob = *e.Blob
+		}
+	case *debug.RemovedEvent:
+		wm.State = domain.DebugEventsStateRemoved
+		wm.Blob = ""
+	}
+}
+
+func (wm *DebugEventsWriteModel) Query() *eventstore.SearchQueryBuilder {
+	return eventstore.NewSearchQueryBuilder(eventstore.ColumnsEvent).
+		ResourceOwner(wm.ResourceOwner).
+		AddQuery().
+		AggregateTypes(debug.AggregateType).
+		AggregateIDs(wm.AggregateID).
+		EventTypes(
+			debug.AddedEventType,
+			debug.ChangedEventType,
+			debug.RemovedEventType,
+		).
+		Builder()
+}