KfComponentsHolder cleanup

Cleanup of KfComponentsHolder.
It became a bit more urgent due to changes introduced by thread-safety.
Restore the timing performance of the Chi2MeasurementEstimator (still pretty deceiving though).

No regression expected, no regression observed
@VinInn @StoyanStoynev 
IIUC, the variable `AlgebraicROOTObject<N,5>::Matrix H` is not used anymore when setting the `KfComponentsHolder` (see the `KfComponentsHolder::setup` template function). This happens because the heavy matrix multiplication was replaced with addressing in `KfComponentsHolder`, so this matrix is not needed anymore, right?