[BP MB-39994] - After KillAndRespawn, from-now directive ignored

As seen in a recent support case, if KillAndRespawn restarts consumer when there is no checkpoint, it starts from 0. However, if user had requested running "From Now", this is incorrect behavior as it must start from current seq no and not 0. So in other words, missing checkpoint must be interpreted as 0 only if boundary was everything; if it was from-now, then missing checkpoint must be interpreted as current sequence number