Show ellipses for leaving rooms and space actions, and always confirm

The HIG suggests using ellipses for actions that have a confirmation,
and leaving a space or room is one such cases. Otherwise, the user has
no idea if leaving is an immediate, irreversible action.

It turns out there *was* some cases where pressing this button
(especially for spaces) would actually do it without confirmation, which
is now fixed.

src/roominfo/RoomInformation.qml

@@ -153,7 +153,7 @@ QQC2.ScrollView {
             Delegates.RoundedItemDelegate {
                 id: leaveButton
                 icon.name: "arrow-left-symbolic"
-                text: root.room.isSpace ? i18nc("@action:button", "Leave this space") : i18nc("@action:button", "Leave this room")
+                text: root.room.isSpace ? i18nc("@action:button", "Leave this space…") : i18nc("@action:button", "Leave this room…")
                 activeFocusOnTab: true
 
                 Layout.fillWidth: true

src/rooms/RoomContextMenu.qml

@@ -152,7 +152,7 @@ KirigamiComponents.ConvergentContextMenu {
     }
 
     QQC2.Action {
-        text: i18n("Leave Room")
+        text: i18n("Leave Room…")
         icon.name: "go-previous"
         onTriggered: {
             Qt.createComponent('org.kde.neochat', 'ConfirmLeaveDialog').createObject(root.QQC2.ApplicationWindow.window, {

src/rooms/SpaceListContextMenu.qml

@@ -70,8 +70,10 @@ KirigamiComponents.ConvergentContextMenu {
     }
 
     QQC2.Action {
-        text: i18nc("'Space' is a matrix space", "Leave Space")
+        text: i18nc("'Space' is a matrix space", "Leave Space…")
         icon.name: "go-previous"
-        onTriggered: root.room.forget()
+        onTriggered: Qt.createComponent('org.kde.neochat', 'ConfirmLeaveDialog').createObject(root.QQC2.ApplicationWindow.window, {
+            room: root.room
+        }).open();
     }
 }

src/spaces/SpaceHomePage.qml

@@ -95,9 +95,11 @@ ColumnLayout {
                     }
                 }
                 QQC2.Button {
-                    text: i18nc("@action:button", "Leave this space")
+                    text: i18nc("@action:button", "Leave this space…")
                     icon.name: "go-previous"
-                    onClicked: root.room.forget()
+                    onClicked: Qt.createComponent('org.kde.neochat', 'ConfirmLeaveDialog').createObject(root.QQC2.ApplicationWindow.window, {
+                        room: root.room
+                    }).open();
                 }
                 Item {
                     Layout.fillWidth: true