[MQ] Fixes for memory leaks
- Make sure that Histo servers gets the right number of parts even if no histos/no canvases to configure or send
- Remove extendable axis in histos of CbmAlgoBuildRawEvents as they cannot be merged
- Do not send STOP command after EOF in CbmMQTsSamplerRepReq
- Pre-book capacity in typical range for input vectors in DigiEventBuilder device