Add filter icon on clips

As suggested here:
https://forum.shotcut.org/t/any-way-to-quickly-see-which-clip-has-filters-on/47468

Author: bmatherly

src/models/multitrackmodel.cpp

@@ -2291,6 +2291,7 @@ void MultitrackModel::filterAddedOrRemoved(Mlt::Producer *producer)
             QVector<int> roles;
             roles << FadeInRole;
             roles << FadeOutRole;
+            roles << IsFilteredRole;
             emit dataChanged(modelIndex, modelIndex, roles);
         }
     } else

src/qml/views/timeline/Clip.qml

@@ -31,6 +31,7 @@ Rectangle {
     property bool isBlank: false
     property bool isAudio: false
     property bool isTransition: false
+    property bool isFiltered: false
     property var audioLevels
     property int fadeIn: 0
     property int fadeOut: 0
@@ -425,6 +426,29 @@ Rectangle {
         }
     }
 
+    ToolButton {
+        visible: !elided && !isBlank && parent.height > 20 && isFiltered
+        icon.name: 'view-filter'
+        icon.source: 'qrc:///icons/oxygen/32x32/status/view-filter.png'
+        icon.width: 16
+        icon.height: 16
+        anchors.left: parent.left
+        anchors.bottom: parent.bottom
+        anchors.bottomMargin: 4
+        anchors.leftMargin: 4
+        width: 20
+        height: 20
+        padding: 1
+        focusPolicy: Qt.NoFocus
+        onClicked: {
+            clipRoot.clicked(clipRoot, null);
+            timeline.filteredClicked();
+        }
+        Shotcut.HoverTip {
+            text: qsTr('Filters')
+        }
+    }
+
     Shotcut.TimelineTriangle {
         id: fadeInTriangle
 

src/qml/views/timeline/Track.qml

@@ -86,6 +86,7 @@ Rectangle {
             isBlank: typeof model.blank !== 'undefined' ? model.blank : false
             isAudio: typeof model.audio !== 'undefined' ? model.audio : false
             isTransition: typeof model.isTransition !== 'undefined' ? model.isTransition : false
+            isFiltered:  typeof model.filtered !== 'undefined' ? model.filtered : false
             audioLevels: typeof model.audioLevels !== 'undefined' ? model.audioLevels : ""
             width: typeof model.duration !== 'undefined' ? model.duration * timeScale : 0
             height: trackRoot.height