flow/bypass: app-layer/stream resources not freed when bypass activated
When a flow bypass is activated, the flow holds on to whatever memory is used in the app-layer and stream. These will finally be freed at the end of the flow. This is not efficient, as after the bypass no code paths will use the app-layer state, transactions or segments.
We might want to hold on to the Tcp session, as this is where TCP packet flags are taken from.