Clean up MessageDelegate.

Include a generic component for text bubbles.
Fixes #11.

qml/component/TextDelegate.qml

@@ -0,0 +1,52 @@
+import QtQuick 2.9
+import QtQuick.Controls 2.2
+import QtQuick.Controls.Material 2.2
+import QtQuick.Layouts 1.3
+
+Rectangle {
+    property bool flat: false
+    property bool highlighted: false
+    property string displayText
+    property alias timeLabelVisible: timeText.visible
+
+    property int maximumWidth
+
+    readonly property bool darkBackground: highlighted && !flat
+
+    id: messageRect
+
+    width: Math.min(Math.max(messageText.implicitWidth, (timeText.visible ? timeText.implicitWidth : 0)) + 24, maximumWidth)
+    height: messageText.implicitHeight + (timeText.visible ? timeText.implicitHeight : 0) + 24
+
+    color: flat ? "transparent" : highlighted ? Material.accent : background
+    border.color: Material.accent
+    border.width: flat ? 2 : 0
+
+    ColumnLayout {
+        id: messageColumn
+
+        anchors.fill: parent
+        anchors.margins: 12
+        spacing: 0
+
+        Label {
+            id: messageText
+            Layout.maximumWidth: parent.width
+            text: displayText
+            color: darkBackground ? "white": Material.foreground
+
+            wrapMode: Label.Wrap
+            linkColor: darkBackground ? "white" : Material.accent
+            textFormat: Text.StyledText
+            onLinkActivated: Qt.openUrlExternally(link)
+        }
+
+        Label {
+            id: timeText
+            Layout.alignment: Qt.AlignRight
+            text: Qt.formatTime(time, "hh:mm")
+            color: darkBackground ? "white" : "grey"
+            font.pointSize: 8
+        }
+    }
+}