Provide the ability to download the logs specific to a job

[chkeita]

The proposal is to redirect agent logs to a blob and make it available via the cli.

On the agent

The redirection can happen in onefuzz-telemetry by adding a logic to upload to an append blob.
We should consider splitting the blob into mutliple files to prevent the creation of single very large blob file. The x-ms-blob-append-offset property of the Append block can provide the data needed to decide to create a new log file.

In the cli

cli work will be done in #1714

[tevoinea]

Are we going to set a retention period for these blobs as well? We could probably mirror log analytics and do 90 days.