Add new sensor types to Transmission sensor

Currently the active torrents count isn’t that useful if you tend to seed torrents, it would be very nice to have the uploading count and downloading count exposed as well as maybe the error count, stopped and completed counts.

It looks like the “State” text is already based on the uploading and downloading count so the numbers are already there in the plugin that could be exposed.

Only those attributes are supported:

https://pythonhosted.org/transmissionrpc/reference/transmissionrpc.html#id1

https://github.com/home-assistant/home-assistant/pull/14530

Odd I guess general front end clients then just iterate through all the torrents to get the totals for Downloading, Seeding, Error state etc.