Auto-expand room pane to show settings/profiles

If the room pane is below the default width (by user resizing or because
of narrow window), go to the room settings or a member profile will
automatically expand it as needed.

The pane goes back to its previous size once the settings/profile is
left.

If the window is narrow enough that expanding the pane normally would
reduce the timeline's width past its minimum, the pane is shown as an
overlay instead.

src/gui/Base/MultiviewPane.qml

@@ -14,12 +14,21 @@ HDrawer {
     property int buttonWidth:
         buttonRepeater.count > 0 ? buttonRepeater.itemAt(0).implicitWidth : 0
 
+    property bool requireDefaultSize: false
+
     readonly property alias buttonRepeater: buttonRepeater
     readonly property alias swipeView: swipeView
 
 
     defaultSize: buttonRepeater.count * buttonWidth
-    minimumSize: buttonWidth
+    minimumSize: requireDefaultSize ? defaultSize : buttonWidth
+
+    Behavior on minimumSize {
+        HNumberAnimation {
+            overshoot: requireDefaultSize ? 1 : 4
+            factor: 0.75
+        }
+    }
 
     HColumnLayout {
         anchors.fill: parent

src/gui/Pages/Chat/Chat.qml

@@ -74,7 +74,15 @@ Item {
 
     HLoader {
         id: loader
-        anchors.rightMargin: ready ? roomPane.visibleSize : 0
+        anchors.rightMargin:
+            ready &&
+            ! (
+                roomPane.requireDefaultSize &&
+                roomPane.minimumSize > roomPane.maximumSize
+            ) ?
+            roomPane.visibleSize :
+            0
+
         anchors.fill: parent
         visible:
             ready ? ! roomPane.hidden || anchors.rightMargin < width : true

src/gui/Pages/Chat/RoomPane/MemberView/MemberView.qml

@@ -10,6 +10,8 @@ HColumnLayout {
     readonly property var modelSyncId:
         [chat.userId, chat.roomId, "filtered_members"]
 
+    readonly property alias viewDepth: stackView.depth
+
 
     HStackView {
         id: stackView

src/gui/Pages/Chat/RoomPane/RoomPane.qml

@@ -32,6 +32,9 @@ MultiviewPane {
     buttonWidth:
         buttonRepeater.count >= 1 ? buttonRepeater.itemAt(1).implicitWidth : 0
 
+    requireDefaultSize:
+        swipeView.currentIndex !== 0 || swipeView.currentItem.viewDepth > 1
+
     buttonsBackgroundColor: theme.chat.roomPane.topBar.background
     background: Rectangle { color: theme.chat.roomPane.background }