Fix row spacing in the command completer

Currently no row spacing exists in the command completer. Add row spacing
to make it prettier.

resources/qml/Completer.qml

@@ -103,7 +103,7 @@ Control {
         // on each side of a row, 1px of padding above the first item and below the last item, and nominally
         // some kind of content height.  avatarHeight is used for just about every delegate, so we're using
         // that until we find something better.  Put is all together and you have the formula below!
-        implicitHeight: Math.min(contentHeight, 6 * rowSpacing + 7 * (popup.avatarHeight + 2 * rowMargin))
+        implicitHeight: Math.min(contentHeight, 6 * Nheko.paddingSmall + 7 * (popup.avatarHeight + 2 * rowMargin))
 
         // Broken, see https://bugreports.qt.io/browse/QTBUG-102811
         //reuseItems: true
@@ -153,7 +153,7 @@ Control {
 
                     RowLayout {
                         anchors.centerIn: centerRowContent ? parent : undefined
-                        spacing: rowSpacing
+                        spacing: Nheko.paddingSmall
 
                         Avatar {
                             displayName: model.displayName
@@ -178,7 +178,7 @@ Control {
 
                     RowLayout {
                         anchors.centerIn: parent
-                        spacing: rowSpacing
+                        spacing: Nheko.paddingSmall
 
                         Label {
                             color: model.index == popup.currentIndex ? palette.highlightedText : palette.text
@@ -213,7 +213,7 @@ Control {
 
                     RowLayout {
                         anchors.centerIn: parent
-                        spacing: rowSpacing
+                        spacing: Nheko.paddingSmall
 
                         Label {
                             color: model.index == popup.currentIndex ? palette.highlightedText : palette.text
@@ -231,7 +231,7 @@ Control {
 
                     RowLayout {
                         anchors.centerIn: centerRowContent ? parent : undefined
-                        spacing: rowSpacing
+                        spacing: Nheko.paddingSmall
 
                         Avatar {
                             displayName: model.roomName
@@ -256,7 +256,7 @@ Control {
 
                     RowLayout {
                         anchors.centerIn: parent
-                        spacing: rowSpacing
+                        spacing: Nheko.paddingSmall
 
                         Avatar {
                             displayName: model.roomName