Fixed origins api for pypi components throwing 500 error when invalid package is provided

[yashkohli88]

Below are the tasks completed as a part of this fix -

• Code updated to introduce try-catch block which checks if the error status code is 404, it returns an empty response. It throws error in other scenarios.
• A separate function has been created to refactor the existing code which contained repeated set of statements, and to perform unit testing on the changes.
• encodeURIComponent has also been introduced where we are creating URL to prevent injection.
• New Test cases added for happy path and two error scenarios with status code 404 and 400 to check the response.
• Fixture added for the response of the positive testcase.

List of testcases added in the origins.js file related to the changes -

• Return proper response when valid package is provided as input
• Return blank response when invalid package is provided as input
• Throws error response when error other than invalid package (status 404) is returned from package manager response.

This fix is related to Issue 1182

[elrayle]

Nice to see 500 errors being addressed. Thanks!

[elrayle]

@yashkohli88 The PR is marked as a work in progress. Is this ready for review? NOTE: There are some conflicts to resolve.