add legacy setup.* files, requird for RPM build on EL8/EL9

CHANGELOG.md

@@ -7,7 +7,7 @@
 * Enhancement: permit_delete_collection can be now controlled also per collection by rights 'D' or 'd'
 * Add: option [rights] permit_overwrite_collection (default=True) which can be also controlled per collection by rights 'O' or 'o'
 * Fix: only expand VEVENT on REPORT request containing 'expand'
-* Adjustment: switch from setup.py to pyproject.toml
+* Adjustment: switch from setup.py to pyproject.toml (but keep files for legacy packaging)
 * Adjustment: 'rights' file is now read only during startup
 * Cleanup: Python 3.7 leftovers