Add persistent storage feature

src/ts/storage/persistant.ts

@@ -0,0 +1,61 @@
+import { get } from "svelte/store";
+import { DataBase } from "./database";
+import { alertNormal } from "../alert";
+import { language } from "src/lang";
+import { isNodeServer, isTauri } from "./globalApi";
+
+async function requestPersistantStorageMain() {
+    
+    if(navigator.storage && navigator.storage.persist) {
+
+        if(await navigator.storage.persisted()) {
+            return true;
+        }
+
+        //if is chromium
+        //@ts-ignore
+        const isChromium = window.chrome;
+        if (isChromium) {
+            //chromium requires notification to persist
+            alertNormal("For chromium based browsers, you need to allow notifications to persist data")
+            const status = await Notification.requestPermission()
+            
+            if(status === 'granted') {
+                return navigator.storage.persist();
+            }
+        }
+
+        const isFirefox = navigator.userAgent.indexOf("Firefox") !== -1;
+
+        if(isFirefox) {
+            //firefox can just ask for persist
+            return navigator.storage.persist();
+        }
+
+        return false;
+    }
+    return false
+}
+
+export async function persistantStorageRecommended() {
+    const db = get(DataBase)
+    if(navigator.storage && navigator.storage.persist && (!isTauri) && (!isNodeServer)) {
+        if(await navigator.storage.persisted()) {
+            return false;
+        }
+        if(db.characters.length > 5){
+            return true;
+        }
+    }
+    return false;
+}
+
+export async function requestPersistantStorage() {
+    const status = await requestPersistantStorageMain();
+    if(status) {
+        alertNormal(language.persistentStorageSuccess)
+    } else {
+        alertNormal(language.persistentStorageFail)
+    }
+    return status;
+}