The hit errors initialization in VeloKalmanHelpers

The MR: !2612 (merged)

which introduced not negligible changes for the Primary Vertex reconstruction as shown in update reference (PrimaryVertexChecker): Moore!1752 (merged) and in @adudziak's presention: link

The change has been introduced since Moore v53r7.

Present hit error initialization slightly decreases global efficiency (~ -2 p.p.) and increases global fake rate (~ +2 p.p.).

We would like to reintroduce a change in VeloKalmanHelpers fitForward(), fitBackward(), fitBackwardWithMomentum() methods:

F( VeloKalmanParam::wx ) -> 100.f 
F( VeloKalmanParam::wy) -> 100.f

The origin of this difference must be followed up and understood.

(cc @dovombru, @mveghel)