Add LOO and cross-drug test matrix generation

[AbhirupaGhosh]

Added functions to build leave-one-out and cross-drug test matrices from parquet files. Updated the main matrix generation function to include calls to these new functions.

Description

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• Feature (adds or updates new capabilities)
• Bug fix (fixes an issue).
• Enhancement (adds functionality).
• Breaking change (these changes would cause existing functionality to not work as expected).

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