Merged requested to merge thboettc_update_gaudi_allen_converters into master
Updates the Velo and Velo-UT Allen-Gaudi track converters to use the current event model. Also removes the redundant seeding + matching track converter.
This MR also removes a bug in the seeding + matching track converter that resulted in each SciFi hit in the converted tracks having the same LHCbID.
Should be tested with Moore!2055 (merged). Resolves #396 (closed).