tdf#120787: fine-tune window flags w/ focus on floating toolbars

Floating toolbars are tool windows (Qt::Tool, not Qt::Window which
has a separate taskbar entry). They are frameles
(Qt::FramelessWindowHint) bc LibO takes care of drawing window
decorations itself. They also must be able to receive keyboard focus
(remove Qt::WindowDoesNotAcceptFocus)

Change-Id: I61e8a905fdc4fde1a64df5a0824d358036cfcdea
Reviewed-on: https://gerrit.libreoffice.org/67768
Tested-by: Jenkins
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>

vcl/qt5/Qt5Frame.cxx

@@ -93,6 +93,11 @@ Qt5Frame::Qt5Frame(Qt5Frame* pParent, SalFrameStyleFlags nStyle, bool bUseCairo)
     {
         if (nStyle & SalFrameStyleFlags::INTRO)
             aWinFlags |= Qt::SplashScreen;
+        // floating toolbars are frameless tool windows
+        // + they must be able to receive keyboard focus
+        else if ((nStyle & SalFrameStyleFlags::FLOAT)
+                 && (nStyle & SalFrameStyleFlags::OWNERDRAWDECORATION))
+            aWinFlags |= Qt::Tool | Qt::FramelessWindowHint;
         else if (nStyle & (SalFrameStyleFlags::FLOAT | SalFrameStyleFlags::TOOLTIP))
             aWinFlags |= Qt::ToolTip;
         else if ((nStyle & SalFrameStyleFlags::FLOAT)
@@ -102,8 +107,6 @@ Qt5Frame::Qt5Frame(Qt5Frame* pParent, SalFrameStyleFlags nStyle, bool bUseCairo)
             aWinFlags |= Qt::Dialog;
         else if (nStyle & SalFrameStyleFlags::TOOLWINDOW)
             aWinFlags |= Qt::Tool;
-        else if (nStyle & SalFrameStyleFlags::OWNERDRAWDECORATION)
-            aWinFlags |= Qt::Window | Qt::FramelessWindowHint | Qt::WindowDoesNotAcceptFocus;
         else
             aWinFlags |= Qt::Window;
     }