r22: cleanup TRT dEdx tool and harmonise use of TRT raw data

This MR harmonises the interpretation of the bit patterns of TRT hits and removes code duplication. It also removes superfluous parts of the TRT dEdx tool and moves the calculation of the time over threshold to the DriftCircle object, where it belongs.

This is a summary of the changes and expected side effects:

1. Only a single implementation of the bit pattern interpretation in TRT_LoLumRawData, re-used by TRT_DriftCircle.
2. The relevant bit pattern is now always the (first) largest consecutive pattern of 1s ("largest island") within the time window. In particular, this is used to identify the relevant 0->1 transition to determine the drift time and thus the drift radius, as well as the time over threshold (= size of largest island). The drift time used to be determined from the first 0->1 transition instead, which is much less robust for high pile-up. This can change the hit position used in track fits and will thus change the resulting tracks.
3. Major clean up of the dEdx tool to remove unused methods and code duplication. Clients can no longer override the settings of the dEdx tool when getting dEdx which allows to remove some redundant parameters from TrackSummaryTool.

Pinging @hansenph, @calfayan.