When dropping an effect on an AV group, apply effect on correct part even if...

When dropping an effect on an AV group, apply effect on correct part even if audio effect is dropped on video
Related to #1047

src/timeline2/model/timelinemodel.cpp

@@ -3725,7 +3725,14 @@ std::shared_ptr<ClipModel> TimelineModel::getClipPtr(int clipId) const
 bool TimelineModel::addClipEffect(int clipId, const QString &effectId, bool notify)
 {
     Q_ASSERT(m_allClips.count(clipId) > 0);
-    bool result = m_allClips.at(clipId)->addEffect(effectId);
+    // Check if we are applying an audio effect on an audio clip
+    bool isAudio = EffectsRepository::get()->isAudioEffect(effectId);
+    bool audioClip = m_allClips.at(clipId)->isAudioOnly();
+    if (isAudio != audioClip) {
+        // Check if we have a split partner
+        clipId = getClipSplitPartner(clipId);
+    }
+    bool result = clipId > -1 && m_allClips.at(clipId)->addEffect(effectId);
     if (!result && notify) {
         QString effectName = EffectsRepository::get()->getName(effectId);
         pCore->displayMessage(i18n("Cannot add effect %1 to selected clip", effectName), ErrorMessage, 500);