Summary:

Stack contains changes that updates overall environment setup flow for vscode extension.

No functional Changes in this diff.

Test Plan:

Summary:

Stack contains changes that updates overall environment setup flow for vscode extension.

This diff implements the server side endpoint. Will test on top with vscode

Test Plan:
```
payload={'env_file_path': {}}
Status Code: 400
Response JSON: {'message': 'Invalid request, specified .env file path is not a string.'}

payload={'env_file_path': '/hi'}
Status Code: 400
Response JSON: {'message': 'Specified .env file path does not exist.'}

payload={'env_file_path': '.env'}
Status Code: 200
Response JSON: {'message': 'Updated .env file path.'}
```

Summary:

Test Plan: