Enhance CORS configuration with allowed domains from settings

[medchedli]

Introduce a method to fetch allowed domains from settings and enhance CORS configuration by combining these domains with those specified in the environment.

Important considerations :

Issue 1 :

• The current implementation fetches allowed domains from the settings service synchronously during the application bootstrap. While this works for initial loading, it doesn't inherently support real-time updates if the settings change after the server has started.
• To achieve truly dynamic CORS configurations that reflect real-time changes in the settings, consider implementing a mechanism to update the allowed domains without restarting the server. This can be done using:
  • Event Emitters: Emit an event whenever the settings related to allowed_domains are updated, and update the CORS configuration accordingly.
  • Polling: Periodically fetch the latest settings and update the allowed domains.

Issue 2 :

• Mixing configuration sources (settings service and .env) can lead to inconsistencies and make it harder to track where specific configurations originate.

Issue 3 :

• Fetching allowed domains from the database can introduce latency, especially if the database is under heavy load.
• Implement caching mechanisms to store allowed domains in memory, reducing the need for frequent database queries.