feat: init migrations for transactional tables (#9946)

# Which Problems Are Solved

To start with transactional tables we need to setup the new `zitadel`
schema in a way that does not rely on the event store later.

# How the Problems Are Solved

Setup step added which calls the function which executes the migrations.

# Additional Changes

none

# Additional Context

- closes #9933

backend/main.go

@@ -3,8 +3,8 @@
 // to get an overview i would start in the api package.
 package main
 
-import "github.com/zitadel/zitadel/backend/cmd"
+// import "github.com/zitadel/zitadel/backend/cmd"
 
-func main() {
-	cmd.Execute()
-}
+// func main() {
+// 	cmd.Execute()
+// }