Azure blob store on-the-fly gzip compression

### Expected Behaviour
Azure blob storage seems to support on-the-fly `gzip` compression that can be enabled for a configurable list of mime-types: https://docs.microsoft.com/en-us/azure/cdn/cdn-improve-performance. For text-based files such as JSON, gzip compression would greatly reduce bytes that need to be send across the wire to a client, e.g. browser.

### Actual Behaviour
Currently, files stored in Azure blob store via `aio-lib-files` are returned uncompressed as-is.

### Reproduce Scenario (including but not limited to)

#### Steps to Reproduce
- upload a JSON file via the `aio-lib-files` library
- generate a presigned url
- download and observe the response and size of the file uploaded above

#### Platform and Version
nodejs:12

Start by tracing the Azure blob upload and presigned URL flow in aio-lib-files, using the JSON upload and download scenario described in the issue. The work is done when eligible text-based files are served with gzip compression and the downloaded response is smaller, while other configured MIME types remain supported.

Written by the indexing model from the issue text.