Fix autosave functionality and dirty state logic

[zeelsheladiya]

Pull Request

This PR addresses critical issues with the editor's data persistence and state management. It fixes a bug where autosave was failing to trigger and corrects the dirty state logic to accurately reflect unsaved changes, ensuring the indicator clears when content matches the saved version.

Description

• Fixed a critical bug where the autosave mechanism was not triggering because the onChange callback was not being called in the Editor
• Refactored BufferStore to include a savedContent field for each buffer.
• Updated updateBufferContent and markBufferDirty to use savedContent for accurate dirty state calculation. This resolves the issue where the dirty indicator would remain active even after reverting changes to the original state.
• Ensured that onChange is correctly propagated from useEditorStateStore to the Editor

Screenshots/Videos

Related Issues

Closes # Fixes #