Do not query MT when doing analysis in batch mode without MT pre-translation

Currently MT is always queried, when doing an analysis in batch mode. Even if MT pre-translation is off. This produces a lot of unnecessary costs and must be changed. It should only be queried, if MT pre-translation is on. And even for pre-translation only those segments should be send to the MT, that have an empty target - not all.

In a first step we could simply implement, that if pre-translation is off, the batch-cache for the MT gets the match-rate defined for the MT in the configuration for all segments without querying the MT at all.

In a second step we could somehow mark, which segments where already send to the TM and then the MT worker would only send those to MT, that are not pre-translated but already queried with all assigned TMs.