Issue2178 better downloader logging

[otsakir]

Added more verbose logging when Downloader throws an error. Testsuite has been run locally with no major findings but at the same time comparing results with master branch has not been consistent.

This is about #2178

[maria-farooq]

@otsakir just a side comment on RCML download failure.
If download fails with http status notFound then, i see VI adds/sends notification.
otherwise call fails.

@gvagenas @deruelle do you think a notification should be added/sent in case of other failures as well (other than NotFound)

i am discussing RCML download failure.
now there can be many reason for above failure.

1. = NOTFOUND
2. = AnythingElse
   both are RCML download failure.
   currently we only add/send notification for case 1.

[maria-farooq]

Quoting @gvagenas [12:22 PM]

Oh I see your point. I agree, we should add notification for (2) also.

@otsakir do you think we can sample notification code like we have for case 1 in case 2 as well or you think its too much (in that case we can create a separate issue)