Make `RedisConnection.sendCommandsImmediately` public

Motivation:

During the refactor work (commit ea7c755d) that was merged with MRs !71 and !53 - `sendCommandsImmediately` was accidentally lowered to `internal`

Modifications:

Properly mark `RedisConnection.sendCommandsImmediately` as `public`

Result:

Developers should now have proper access to the `sendCommandsImmediately` property