Channel Assignment TrackBuilder output Tracks + Stubs and InputRouter input Stubs

[tschuh]

This PR does:

• updates TrackBuilderChannel::channelId using now TTTrackRef instead of TTTrack
• extends TrackBuilderChannel to assign TTStubs from found TTTracks to channel
• trackFindingTracklet::ProducerKFin uses now TTTrackRefs to get channelIds via TrackBuilderChannel
• ProducerTrackBuilderCannel construct TrackBuilderChannel with Setup which is needed to assign stubs to channel
• adds a map of which DTC links are used in summer chain configuration as python config
• adds seed type names, seeding layer Ids per seed type and projection layers per seed type as python config I add constants which are somehow somewhere already present in the tracklet pattern reco c++ to python configuration. This needs rethinking, advise is welcome.

[tschuh]

Renamed TrackBuilderChannel to ChannelAssignment. One can now run any reduced chains by manipulating ChannelAssignment_cfi.py SeedTypes, MaxNumProjectionLayers, SeedTypesSeedLayers, SeedTypesProjectionLayers and IRChannelsIn.

[tschuh]

I renamed the config parameter so to make clear that those are subsets of other parameter. I added a consistency check so that one cannot invent new seed types are projection layer within these subsets.

[tomalin]

@tschuh Please check that you have responded to all comments, so this PR can be approved.