Make all the URLs, parameters as environment variables

[Perevalov]

Context

Currently in the code all the URLs (e.g., here or here) and global parameters are hardcoded. It should be changed to environment variables. The variables to be set via dotenv if an .env file is present locally, otherwise directly imported from os.getenv("VAR_NAME").

Definition of Done

• Check all the hardcoded parameters and URLs
• Change the identified ones to the env variables
• Test if everything still works as before
• Push the code

[muskan-k]

Done, tested and verified.
PR - #17
PR - #18

I've also edited the GA workflow to be triggered on pull requests to main branch as well, instead of only being triggered on merge since the best practice is check the build on PRs as a gateway to being merged.