[PWGCF] Update DCA check

[fsii]

1. Add check of centrality dependence of DCA
2. Update default values of configurables
3. Enable cut for MC z-vtx
4. New interpolation of TH3

[github-actions]

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[Copilot]

Pull request overview

This PR updates the EbyE particle-number fluctuation task to support a centrality-dependent DCA QA, refreshes several configurable defaults, enables an MC z-vertex selection cut via a configurable threshold, and replaces ROOT’s TH3::Interpolate usage with a custom interpolation routine for PID shift maps.

Changes:

• Switch DCA QA from (pT, η, φ) dependence to (centrality, pT, η) using a new centrality calibration axis.
• Introduce centralityCalibration (optionally distinct from the analysis centrality definition) and use NTPV centrality for QA/calibration by default.
• Update MC handling/configurables (MC z-vtx cut threshold, PROCESS_SWITCH macros) and implement custom TH3 interpolation for NSigma shift recalibration.

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