Mostly backend models stuff

Changed some models, did some work on database, created a class diagram.

KTUSA PS/ClientApp/src/main.js

@@ -3,15 +3,10 @@ import { createApp } from "vue";
 import App from "./App.vue";
 import router from "./router";
 import store from "./store";
-import BalmUI from "balm-ui"; // Official Google Material Components
-import BalmUIPlus from "balm-ui-plus"; // BalmJS Team Material Components
-import "balm-ui-css";
 
 const app = createApp(App);
 
 app.use(router);
 app.use(store);
-app.use(BalmUI);
-app.use(BalmUIPlus);
 
 app.mount("#app");