K8S adapter should build runner image in prerunner

[f1ames]

Feature description

This is a follow-up of https://github.com/scramjetorg/transform-hub/pull/247. For now, runner pod works in a way that it is started first (with while loop waiting for sequence files to be copied), then sequence files are being copied and run. This makes the flow a bit confusing and requires workaround to keep runner pod running.

To fix this, we have concluded that prerunner should build runner image (with sequence files already there), snapshot it and then pass snapshot reference to runner. This way runner pod when started will already have all sequence files and can execute it right away. Also it should simplify the whole runner flow.