Complete Py_AASequence implementation with tests and security checks

Co-authored-by: timosachsenberg <5803621+timosachsenberg@users.noreply.github.com>

Author: Copilot

openms_python/py_aasequence.py

@@ -277,3 +277,4 @@ def has_suffix(self, suffix: str) -> bool:
             bool: True if sequence ends with suffix.
         """
         return self._sequence.hasSuffix(oms.AASequence.fromString(suffix))
+