Refactoring default header in fetch.js in Service

[yashkohli88]

Overview

This pull request is aimed at refactoring the fetch.js file to introduce a defaultHeader variable. This variable will be used as the default header across all Axios requests within the service repository, providing a more streamlined and maintainable approach to request configuration.

Tasks Completed

1. Introduction of defaultHeader:

• Implemented a defaultHeader variable in the fetch.js file to serve as a default header. This header is now included in the Axios global configuration to ensure it is applied to every request automatically.

2. User-Agent Header Replacement:

• - Replaced instances of the withDefaults function across the codebase with callFetch. This change enables to control all the default headers from a centralized file.
• - Updated various parts of the service repository to replace individual user-agent header entries with the global defaultHeader, promoting uniformity and reducing the risk of errors or omissions.

3. Test Case Updates:

• - Modified test cases to incorporate the global defaultHeader, ensuring that the tests remain accurate and reflective of the new header setup.
• - New unit test cases are also added to increase test coverage for the changes.
• - Origins API test integration ran on the new code to ensure the regression test cases are working fine.

This PR is related to #1090