FEAT: Make EmbeddedChat more mobile responsive

[Spiral-Memory]

As an EmbeddedChat developer:

I need to:
Make EmbeddedChat more mobile-friendly, though it currently is.

So that:
It works well on mobile devices and in smaller-sized integrations.

Acceptance Criteria:

• Identify potential issues on smaller screens.
• Fix those issues to make the platform mobile-friendly.

Some known issues include:

1. On smaller screen sizes, the modal takes up the entire screen. It would be better to have some spacing, with the popups centered.
2. On smaller screens, the sidebar should open as a full-page view, covering the entire screen, with an option to go back.
3. Currently, the popups are strictly positioned. A more flexible positioning system is required. On mobile devices, these popups can act as modals or pages whichever suits better.
4. There may be additional responsive issues, and addressing as many of them as possible is appreciated.

Happy contributing!

[Spiral-Memory]

Feel free to contribute to this issue. Your help is greatly appreciated.

[ghost]

@Spiral-Memory I really wanted to improve its UI too and improve the responsiveness a little more.