Rework upload to use direct storage URIs if avaialble.

[haiodo]

Upload process should be following:

1. To improve upload performance, we need to have few steps, first create uploading Blob and return direct upload url.
2. Do upload to url.
3. Update blob with a proper information from storage.

Download process should be following:

1. To prevent same-origin issue and just opening of document instead of download we need to provide a CF worker /files/ compatible API to access file.

Refs:

• Chrome 65 and above only supports same-origin download links.
• Firefox only supports same-origin download links.

_{Huly®: UBERF-7322}