feat(eventstore): increase parallel write capabilities (#5940)

This implementation increases parallel write capabilities of the eventstore.
Please have a look at the technical advisories: [05](https://zitadel.com/docs/support/advisory/a10005) and  [06](https://zitadel.com/docs/support/advisory/a10006).
The implementation of eventstore.push is rewritten and stored events are migrated to a new table `eventstore.events2`.
If you are using cockroach: make sure that the database user of ZITADEL has `VIEWACTIVITY` grant. This is used to query events.

cmd/setup/15.go

@@ -0,0 +1,45 @@
+package setup
+
+import (
+	"context"
+	"embed"
+
+	"github.com/zitadel/logging"
+
+	"github.com/zitadel/zitadel/internal/database"
+)
+
+var (
+	//go:embed 15/cockroach/*.sql
+	//go:embed 15/postgres/*.sql
+	currentProjectionState embed.FS
+)
+
+type CurrentProjectionState struct {
+	dbClient *database.DB
+}
+
+func (mig *CurrentProjectionState) Execute(ctx context.Context) error {
+	migrations, err := currentProjectionState.ReadDir("15/" + mig.dbClient.Type())
+	if err != nil {
+		return err
+	}
+	for _, migration := range migrations {
+		stmt, err := readStmt(currentProjectionState, "15", mig.dbClient.Type(), migration.Name())
+		if err != nil {
+			return err
+		}
+
+		logging.WithFields("file", migration.Name(), "migration", mig.String()).Info("execute statement")
+
+		_, err = mig.dbClient.ExecContext(ctx, stmt)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (mig *CurrentProjectionState) String() string {
+	return "15_current_projection_state"
+}