Add comprehensive test suite with 865 tests for all EntMix functions and methods#3

Copilot wants to merge 3 commits intosmilestillhanke/EntMix:smilesfrom

copilot/fix-e2d1bc14-015f-4809-99db-d65ec6b3fdbctillhanke/EntMix:copilot/fix-e2d1bc14-015f-4809-99db-d65ec6b3fdbcCopy head branch name to clipboard