Introspection scanner: Improve detection of property getter / setter methods
In the current implementation there are some methods detected as property getter / setter methods which do not match the property.
Gst sample: set_latency method is matched with property latency but the method has 2 instead of 1 additional parameter.
Gtk3 table sample: get_row_spacing is matched with row-spacing but the getter requires a parameter to get the row spacing which is not possible for a property.
One idea to workaround this problems is to improve the heuristic to take the number of parameters into account to consider a method a proper match for a property.