Refactor and Optimize Async Devfolio Scrapper

[KavyaMalviya56]

Description:
The current async event scraper code could benefit from refactoring and optimization for better readability and efficiency. Additionally, the code should be organized into a class and incorporate configuration from environment variables.

Tasks:

Refactor the code into a class, encapsulating the related functionality.
Improve code readability by following PEP 8 style guidelines.
Make the MongoDB URI, database name, and endpoint URL configurable as class attributes.
Implement better exception handling for network requests and validation.
Organize the code into distinct methods for easier maintenance.
Add comments to explain the purpose of each method and attribute.

@anupammaurya6767 assign me this issue under hacktoberfest

[anupammaurya6767]

@KavyaMalviya56 go ahead