Fix filters genering wrong data types

When enabling a jitter filter on integer states (e.g. a signal
strength that repeatedly jumps up and down by 1), old code
may cause integer state to be populated with floating point values
as the filtering happens after the intial validation for the new
value being valid.

libnymea/integrations/thing.cpp

@@ -401,6 +401,7 @@ void Thing::setStateValue(const StateTypeId &stateTypeId, const QVariant &value)
             if (filter) {
                 filter->addValue(newValue);
                 newValue = filter->filteredValue();
+                newValue.convert(stateType.type());
             }
 
             QVariant oldValue = m_states.at(i).value();