Refactor file transfer functionality

[maxceem]

• use AWS SDK instead of AWS CLI via exec for transferring files between buckets
• remove a redundant call for ${fileServiceUrl}uploadurl which we don't need anymore in Project Service

This refactoring shouldn't change any functionality and only improves internal code.

[maxceem]

How to test:

• file uploading should work as before
• uploading file to some project https://connect.topcoder-dev.com/projects/8600/assets
• after uploading click the file to open/download it and make sure it works

[lakshmiathreya]

@nithyaasworld

[SathyaJayabal]

@maxceem , I was able to upload, edit and remove files from the assets library of a project in PROD.

[vikasrohit]

Closing the issue.