Improve API4 initialization (#18680)

* Improve API4 initialization

- Refactored openGraphDataCache to be inside app layer.
- Moved the cache instance from global variable to be inside server.
- Moved out the app instantiation from the global commands package
to be instantiated on every call. Only the server instance is passed.
- Moved InitLocal to be called from inside Init.

```release-note
NONE
```

* Remove commented line

```release-note
NONE
```

api4/apitestlib.go

@@ -177,9 +177,8 @@ func setupTestHelper(dbStore store.Store, searchEngine *searchengine.Broker, ent
 		panic(err)
 	}
 
-	Init(th.App, th.App.Srv().Router)
-	InitLocal(th.App, th.App.Srv().LocalRouter)
-	web.New(th.App, th.App.Srv().Router)
+	Init(th.App.Srv())
+	web.New(th.App.Srv())
 	wsapi.Init(th.App.Srv())
 
 	if enterprise {