[PWGLF] Refactor and Rename K892pm flow with Code Improvements

[BongHwi]

1. File and Struct Renaming:
   • Renamed chk892flow.cxx to chk892Flow.cxx to align with standard naming conventions.
   • Updated struct name from chk892flow to chk892Flow for consistency.
2. Code Cleanup and Enhancements:
   • Replaced hardcoded PDG codes with constants from o2::constants::physics::Pdg for better maintainability.
   • Standardized naming conventions across the codebase (e.g., binType → BinType).
   • Added configurable options for minimum and maximum transverse radius of K0s.
   • Enabled QA/K0sCutCheck histogram only when cfgReturnFlag is set.
3. Performance Optimization:
   • Optimized the K0s selection function by grouping common cuts into a lambda function to reduce redundancy.
   • Improved PID selection logic for better efficiency and readability.
   • Removed unused or commented-out histogram definitions to clean up the code.
4. Code Style Improvements:
   • Standardized variable names by adding prefixes (l for local, cfg for configurable variables, still need some improvement).
   • Applied consistent indentation and spacing for readability.

[alibuild]

Error while checking build/O2Physics/o2 for 9bbf026 at 2025-01-27 19:23:

## sw/BUILD/O2Physics-latest/log
CMake Error at cmake/O2PhysicsAddExecutable.cmake:113 (add_executable):
CMake Error at cmake/O2PhysicsAddExecutable.cmake:113 (add_executable):

Full log here.