fix: improve performance (#4300)

## Note

This release requires a setup step to fully improve performance.
Be sure to start ZITADEL with an appropriate command (zitadel start-from-init / start-from-setup)

## Changes

- fix: only run projection scheduler on active instances
- fix: set default for concurrent instances of projections to 1 (for scheduling)
- fix: create more indexes on eventstore.events table
- fix: get current sequence for token check (improve reread performance)

cmd/setup/04.go

@@ -0,0 +1,36 @@
+package setup
+
+import (
+	"context"
+	"database/sql"
+	"embed"
+)
+
+var (
+	//go:embed 04/cockroach/index.sql
+	//go:embed 04/postgres/index.sql
+	stmts embed.FS
+)
+
+type EventstoreIndexes struct {
+	dbClient *sql.DB
+	dbType   string
+}
+
+func (mig *EventstoreIndexes) Execute(ctx context.Context) error {
+	stmt, err := readStmt(mig.dbType)
+	if err != nil {
+		return err
+	}
+	_, err = mig.dbClient.ExecContext(ctx, stmt)
+	return err
+}
+
+func (mig *EventstoreIndexes) String() string {
+	return "04_eventstore_indexes"
+}
+
+func readStmt(typ string) (string, error) {
+	stmt, err := stmts.ReadFile("04/" + typ + "/index.sql")
+	return string(stmt), err
+}