errors should indicate if they came from gocql directly

[Zariel]

All errors which are defined in gocql should indicate that they came from gocql by having a gocql: prefix in the error. This will help users identify where errors come from and potentially be clearer as to why.

[Zariel]

This relates to #281

[justinretailnext]

Alternatively, there could be defined an error type for errors from gocql directly, and an error type for errors from the wire.

[nathany]

Though a somewhat independent concern, Error types or Err constants would be nice.

[OleksiienkoMykyta]

I think #1753 solves the issue. @tengu-alt, I think you can add closes to the issue in your PR