FEAT: Add `Preset` Importer/Exporter for Custom EQ Settings

[BennyPerumalla]

Currently, users who spend time fine-tuning their equalization and amplification settings in Super Dribble have no way to back up their configurations or share them across different devices. If a user clears their browser cache or switches to a new machine, they have to manually recreate their custom presets from scratch, which is tedious and error-prone.

I would like to see an "Import/Export" utility added to the extension settings.

• Export: A button that generates and downloads a .json file containing the user's saved custom presets.
• Import: A file upload trigger that accepts a .json file and populates the user's preset list with the imported configurations.

alternatives you can considered

• Cloud Sync: Using Chrome/Edge storage sync, but this is often limited by storage quotas and doesn't allow for easy sharing between different users.
• Manual Copying: Users could manually copy-paste JSON text into a text area, but a file-based approach is much more user-friendly.

Why is this feature important?
This feature adds significant value by:

1. Portability: Allowing power users to take their "perfect sound" with them across devices.
2. Community Sharing: Enabling users to share their specialized EQ settings for specific genres or hardware (e.g., "Bass Boost for Sony WH-1000XM4") with other Super Dribble users.
3. Data Safety: Providing a manual backup method to prevent loss of custom configurations.

Additional context
The JSON structure should ideally look something like this:

{
  "version": "1.0",
  "presets": [
    {
      "name": "Deep Bass",
      "gains": [6, 4, 2, 0, 0, 0, 0, 0, 0, 0],
      "preamp": 2
    }
  ]
}