Storage Accounts: CORS rules respect format of original URI

[ninjarobot]

This PR closes #1003

The changes in this PR are as follows:

• Storage Accounts: CORS rules respect format of original URI

I have read the contributing guidelines and have completed the following:

• [x] Tested my code end-to-end against a live Azure subscription.
• [ ] Updated the documentation in the docs folder for the affected changes.
• [x] Written unit tests against the modified code that I have made.
• [x] Updated the release notes with a new entry for this PR.
• [x] Checked the coding standards outlined in the contributions guide and ensured my code adheres to them.

If I haven't completed any of the tasks above, I include the reasons why here:

• Bug fix, nothing to update in docs.

[ninjarobot]

@isaacabraham could you please review this? It can have an effect on how you are defining storage account CORS rules if you don't have a path in the URI.

[isaacabraham]

LGTM - Thanks @ninjarobot :-)