Use new Bulk API in seed script

## Problem

Seed script is a bit slow because it is inserting hundreds of rows one by one.

## Solution

Appwrite team recently introduced the [Bulk API](https://appwrite.io/blog/post/announcing-bulk-api). We could update the script to leverage it, and hence make the script faster.

Start by locating the seed script in the repository and read how it currently inserts rows one by one. Review Appwrite's Bulk API documentation, then update the script to use bulk insertion and verify that seeding still creates the expected rows with improved performance.

Written by the indexing model from the issue text.