[BUG] Add request validators to all the routes and change the ENDPOINT.md accordingly

[ighoshsubho]

• v2 of Fintech API repo needs to have validations to all the routes and due to them the endpoints become POST request instead of GET
• After adding request validations to all the routes, test it with the /docs route
• Add the request and responses accordingly in the ENDPOINTS.md

[github-actions]

👋 @ighoshsubho

Thank you for raising an issue. We will investigate into the matter and get back to you as soon as possible.

Please make sure you have given us as much context as possible.

[Codeansh]

Please assign this issue to me, I'll do this.

[DEEKSHACodeaim]

@ighoshsubho, I would like to take this issue , please assign it to me if not yet fixed.

[Codeansh]

I am working on it.

[pooranjoyb]

@ighoshsubho Can you assign me this issue as there hasn't been any activity from last 2 weeks?

[Codeansh]

Actually, I was busy, but now am available and I'll fix it as soon as possible.