WIP: Fix chi2 computation in the track finder

With this fix the track finder chi2 computation is consistent with the search cuts. E.g. if the time search cut is disabled, time residuals will not contribute to the chi2 used to select tracks in the track finder. Previously, all residuals would contribute regardless of the search settings.

The track finder behavior is independent from the subsequent track fit. The track finder can e.g. consider only spatial information while the fitter also takes time into account.