Add support for initialize with initial data file

[guanzhousongmicrosoft]

The database should support initialization from a user-provided file (e.g., .db or .sql). Users will specify a host file path, which will be copied into the container on startup. The database system will then use this file to populate its initial dataset, enabling quick setup with pre-existing data.

[sajeetharan]

Bundling sample data with DocumentDB local offers a smoother out-of-the-box experience and faster onboarding, but could increase the image size do we see that as a concern? Relying on users to import via the extension keeps the image lean and flexible but adds friction and slows down the initial experience.

[tnaum-ms]

I'm fully on board with including sample data :) It's incredibly helpful during onboarding and provides a reliable foundation for future blog posts, tutorials, and documentation.

I'd love to integrate it with the extension so that, even if the user doesn't initialize with the demo data, there's still a simple way to access it.

Specifically:

• Can the data be hosted on GitHub with a static URL?
• Can the data be in JSON format so it's easy to consume in the extension?

[xgerman]

The behavior should look like:

• there will be a flag to enable/disable initializing the database
• we will ship some sample test data
• customers can use -v to supply their own initialization data

We will explore running mogosh in our docker init script to process this

[xgerman]

Mongosh has a way to run js files in a directory so all we need to do is add that to the startup script + provide sample data (Sajee/Tomasz can give us)