Set for menu and float-list-box the PopupModeFlags to
FLOATWIN_POPUPMODE_PATHMOUSECANCELCLICK + FLOATWIN_POPUPMODE_ALLMOUSEBUTTONCLOSE

Improving the comments

Change-Id: I313e4ec38637fa3d46567e08bdb9560ce8475b6a
Reviewed-on: https://gerrit.libreoffice.org/11881Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>