Don't hardcode fonts

Fix hardcoded fonts (again)

resources/qml/InviteDialog.qml

@@ -111,13 +111,13 @@ ApplicationWindow {
                     Label {
                         text: model.displayName
                         color: TimelineManager.userColor(model ? model.mxid : "", Nheko.colors.window)
-                        font.pointSize: 12
+                        font.pointSize: fontMetrics.font.pointSize
                     }
 
                     Label {
                         text: model.mxid
                         color: Nheko.colors.buttonText
-                        font.pointSize: 10
+                        font.pointSize: fontMetrics.font.pointSize * 0.9
                     }
 
                     Item {

resources/qml/RoomMembers.qml

@@ -43,7 +43,7 @@ ApplicationWindow {
         }
 
         Label {
-            font.pixelSize: 24
+            font.pixelSize: fontMetrics.font.pixelSize * 2
             text: members.memberCount + (members.memberCount === 1 ? qsTr(" person in ") : qsTr(" people in ")) + members.roomName
             Layout.alignment: Qt.AlignHCenter
         }
@@ -97,13 +97,13 @@ ApplicationWindow {
                         Label {
                             text: model.displayName
                             color: TimelineManager.userColor(model ? model.mxid : "", Nheko.colors.window)
-                            font.pointSize: 12
+                            font.pointSize: fontMetrics.font.pointSize
                         }
 
                         Label {
                             text: model.mxid
                             color: Nheko.colors.buttonText
-                            font.pointSize: 10
+                            font.pointSize: fontMetrics.font.pointSize * 0.9
                         }
 
                         Item {

resources/qml/RoomSettings.qml

@@ -98,7 +98,7 @@ ApplicationWindow {
 
             MatrixText {
                 text: roomSettings.roomName
-                font.pixelSize: 24
+                font.pixelSize: fontMetrics.font.pixelSize * 2
                 Layout.alignment: Qt.AlignHCenter
             }
 
@@ -264,7 +264,7 @@ ApplicationWindow {
 
             MatrixText {
                 text: roomSettings.roomId
-                font.pixelSize: 14
+                font.pixelSize: fontMetrics.font.pixelSize * 1.2
                 Layout.alignment: Qt.AlignRight
             }
 
@@ -274,7 +274,7 @@ ApplicationWindow {
 
             MatrixText {
                 text: roomSettings.roomVersion
-                font.pixelSize: 14
+                font.pixelSize: fontMetrics.font.pixelSize * 1.2
                 Layout.alignment: Qt.AlignRight
             }