Enhancements: Dropdown Handling, Skipping Marked Questions, and Dynamic API Key Reset

[Gyan172004]

This update introduces key improvements to enhance reliability and flexibility:

1. Skipping Already Marked Questions

   • Implemented a function to detect questions already marked using the DOM.
   • The script now avoids redundant filling by skipping questions that are already answered.
   • Added a toggle to allow users to enable or disable this functionality based on preference.

2. Improved Dropdown Handling

   • Fixed an issue where filling a dropdown failed if a user clicked on it during its open state.
   • Added an invisible overlay to block all user interactions while the dropdown is being handled.
   • The overlay activates before the dropdown opens and remains until the filling process is completed.

3. Dynamic Engine API Key Reset

   • Addressed the problem of static Engine properties persisting across instances, leading to unintended reuse of settings.
   • Ensured that all static properties are reset whenever the user saves new settings, allowing each instance to start with fresh configurations. ----> It has further edits , where i moved code from static based approach to instance based.