[python] Add self-contained Ray datasource and top-level read_paimon/write_paimon API#7740

JingsongLi merged 9 commits into

apache:masterapache/paimon:masterfrom

TheR1sing3un:py-ray-datasource-top-levelTheR1sing3un/incubator-paimon:py-ray-datasource-top-levelCopy head branch name to clipboard