🚀 Feature: Add Thumbnails for Videos on Storage Bucket

### 🔖 Feature description

Currently the preview thumbnail shows the file format thumbnail for a video.
It would be helpful to identify the video without being played if random names are used.

### 🎤 Pitch

Identifying the video without being played would be super helpful.

### 👀 Have you spent some time to check if this issue has been raised before?

- [X] I checked and didn't find similar issue

### 🏢 Have you read the Code of Conduct?

- [X] I have read the [Code of Conduct](https://github.com/appwrite/.github/blob/main/CODE_OF_CONDUCT.md)