Add a Generic Track SOA Container

Implementation of v2 Track container mentioned to #97 (closed) , here named as Generic Tracks. Implements storage of full state covariance information, multiple states per track, and and storage of LHCbID's by subdetector. Currently, an exception is thrown when a state that is undefined for a certain track type is accessed. Associated with Rec!2356 (merged) and Phys!882 (merged) @mramospe @mvesteri @apearce