Return kNotImplemented with vst3_no_scale

Ever since 0bed2b7bc0 REAPER will randomly
not play back one or more audio channels for plugins that support
IPlugViewContentScaleSuport. If you return `kNotImplemented` then this
bug doesn't occur. REAPER should definitely fix this soon. With
`kResultFalse` this issue still occurs, hence this change so you can use
`vst3_no_scale` to work around this REAPER bug.

src/wine-host/bridges/vst3.cpp

@@ -807,7 +807,7 @@ void Vst3Bridge::run() {
                                       << ", but the 'vst3_no_scale' option is "
                                          "enabled. Ignoring the request."
                                       << std::endl;
-                            return Steinberg::kResultFalse;
+                            return Steinberg::kNotImplemented;
                         } else {
                             return main_context
                                 .run_in_context<tresult>([&]() {