Get the full, descriptive error response returned from skyd

[mrcnski]

PULL REQUEST

Overview

Previously, methods were returning error messages that said e.g. "Request failed
with status code 429" and we had to drill down into the actual response to see
what the skyd error was.

All methods that make a request now return a descriptive error message based on
the skyd response message.

• Added ExecuteRequestError which contains the original Axios error. We now
  throw this on network errors instead of AxiosError directly.

• Added request.ts file for ExecuteRequestError. I originally tried putting it in
  client.ts where it was causing circular dependencies and stuff not being defined
  at runtime.

• Also, I fixed a bug where a promise in uploadLargeFile was not being
  rejected on error.

Checklist

Review and complete the checklist to ensure that the PR is complete before assigned to an approver.

• All new methods or updated methods have clear docstrings
• Testing added or updated for new methods
• Verify if any changes impact the WebPortal Health Checks
• Approriate documentation updated
• Changelog file created

[peterjan]

I approved seeing as the code likely works. I do think some of the suggestions I made are worth implementing though.