gtk3+wayland: start floating windows hidden

once they are visible we can't move them under wayland, so
start then hidden, move them and then show

these floating windows are very delicate.

Change-Id: Ia233c23f25cec453df79ef70cab6210dbdd280a0

sfx2/uiconfig/ui/floatingrecord.ui

@@ -3,7 +3,6 @@
 <interface>
   <requires lib="gtk+" version="3.0"/>
   <object class="GtkWindow" id="FloatingRecord">
-    <property name="visible">True</property>
     <property name="can_focus">False</property>
     <property name="no_show_all">True</property>
     <property name="border_width">6</property>

svx/uiconfig/ui/colorwindow.ui

@@ -17,7 +17,6 @@
     <property name="icon_size">1</property>
   </object>
   <object class="GtkWindow" id="palette_popup_window">
-    <property name="visible">True</property>
     <property name="can_focus">False</property>
     <property name="hexpand">True</property>
     <property name="vexpand">True</property>

svx/uiconfig/ui/floatingundoredo.ui

@@ -3,7 +3,6 @@
 <interface>
   <requires lib="gtk+" version="3.0"/>
   <object class="GtkWindow" id="FloatingUndoRedo:border">
-    <property name="visible">True</property>
     <property name="can_focus">False</property>
     <property name="hexpand">True</property>
     <property name="vexpand">True</property>