Raise a proper TypeError when a property assignment cannot be performed

[jhonabreul]

What does this implement/fix?

Fixes a property-assignment bug that surfaced when a Lean Python algorithm assigned a pure-Python object to self.universe_manager (which snake-cases onto QCAlgorithm.UniverseManager { get; private set; }) and got the opaque SystemError: error return without exception set instead of an actionable error:

Converter.ToManagedValue could fail without setting a Python error even when called with setError: true. Three exits returned false silently: the final fall-through (plain Python object with no conversion to an arbitrary CLR class), the reflected-class-object case (converting a CLR class object to something other than Type), and non-MethodBinding managed types (method/module objects). PropertyObject.tp_descr_set trusts setError: true and returns -1, so CPython's release-build eval loop raises SystemError: error return without exception set at the assignment. These exits now set the same '{type}' value cannot be converted to {obType} TypeError the type_error label already uses, preserving any more specific error a probing sub-path (e.g. a throwing implicit operator) left pending.

With the fix, the Lean repro turns from SystemError: error return without exception set into TypeError: 'UniverseManager' value cannot be converted to QuantConnect.Securities.UniverseManager, pointing straight at the offending assignment.

The fix carries its own regression tests, verified red before the fix and green after.

Does this close any currently open issues?

No open issue; root-caused from a Lean user report of error return without exception set during algorithm initialization.

Any other comments?

Python assignment to CLR properties with private setters (via reflection) is intentionally left untouched by this PR.

End-to-end verification against Lean master (the original repro): self.universe_manager = <pure python object> in a Python algorithm now fails with a clear TypeError at the offending line instead of SystemError: error return without exception set.