Replace pandas with polars for better efficiency in core data processing modules#2

Copilot wants to merge 6 commits intomasterRoestlab/pyprophet:masterfrom

copilot/fix-43af53d6-2a7a-4d2d-9144-5f01e2a6bc25Roestlab/pyprophet:copilot/fix-43af53d6-2a7a-4d2d-9144-5f01e2a6bc25Copy head branch name to clipboard