Feature: Add Ctx Version of all Channel / Connection methods

[peake100]

It would be nice to be able to have a version of all Channel methods that can take in a Ctx and exit on error.

[peake100]

I think a good approach to this would be to add a .WithCtx(ctx context.Context) namespace method that returns a type which in turn exposes the method, that way we won't pollute the namespace by doubling up every method.

The API would be something like:

info, err := channel.WithCtx(ctx).QueueInspect("queue_name", false)