Allow to define the required dynamic environment configurations in the same .env.config file.

[suthagar23]

Current flow
Users have to pass their dynamic environment configuration requirements through the server start or dotEnv.

{
   "BFF_URL": "{{BASE_URL}}/api/v1",
}

Here, User have to start the server with BASE_URL in the following way, otherwise, it will be undefined

BASE_URL=https://abc.com yarn start

---

New Requirement

1. Users should able to define their dynamic environment configurations in the same .env.config file.

{
   "BASE_URL" : "https://abc.com",
   "BFF_URL": "{{BASE_URL}}/api/v1",
}

2. Users must define their dynamic environment keys before to the required environment key. (No need to check the BASE_URl after the BFF_URL in the top to bottom order)
3. All other configuration methods need to be the same as for these environment keys as well. Just an example,

{
   "BASE_URL" : { 
        DEV: "https://abc.com",
        DEFAULT: "https://abc.com"
   }
   "BFF_URL": "{{BASE_URL}}/api/v1",
}