Core: Use an aspect for the Patch tool path setting

Change-Id: Ifc758fb4ac5d00a7b755ea06f3f6b98d53e7cc46
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/libs/utils/aspects.cpp

@@ -159,6 +159,11 @@ void BaseAspect::setDefaultVariantValue(const QVariant &value)
     QTC_CHECK(false);
 }
 
+bool BaseAspect::isDefaultValue() const
+{
+    return defaultVariantValue() == variantValue();
+}
+
 QVariant BaseAspect::defaultVariantValue() const
 {
     return {};