Add Description To Data Source Connection

[frithjof_v]

Sometimes, when looking at connections in Manage Gateways and Connections, it's difficult to remember "what's this data source connection being used for"?

It would be good if we could add descriptions to connections, so we can use it as a note for our future self about why this connection was created.

This will in turn be useful when doing connection cleanup (deleting existing connections), for which there isn't really any good solution today to know what a connection is being used for.