feat: validate login passed to background and implemented into add all injected button (#443)

* docs: proper captializing

* docs: confirmed that the for loop is entered but on first startup something else

* feat: turns out - validate login status - not in background - pass background now

* feat: kronk.gif

* Update UserScheduleMessages.ts

* Update addCourseByURL.ts

* chore: format

* chore: chore

---------

Co-authored-by: doprz <52579214+doprz@users.noreply.github.com>

src/shared/messages/UserScheduleMessages.ts

@@ -64,6 +64,14 @@ export interface UserScheduleMessages {
      */
     renameSchedule: (data: { scheduleId: string; newName: string }) => string | undefined;
 
+    /**
+     * Checks the login status by making a request to the provided URL.
+     *
+     * @param data - The URL to check the login status against.
+     * @returns true if user was already logged into the provided URL, false otherwise
+     */
+    validateLoginStatus: (data: { url: string }) => boolean;
+
     /**
      * Exports the current schedule to a JSON file for backing up and sharing
      *