Add server listen functionality to start Express server

[shreyasparaj]

Description

• Added server listening functionality to start the Express server, allowing it to run on the specified port. This enables the server to handle incoming requests and serve static files.

• Previously, the code did not include a listen function for starting the server. Without this functionality, the server could not handle requests, making the API endpoints inaccessible. This update resolves that issue.

• No new dependencies were added for this change.

Fixes # 1443

Type of change

Added server listening functionality

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

[github-actions]

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