- Base SvxCurrencyToolBoxControl on PopupWindowController,
  so we still allow tearoff, but without marking the window
  as self-decorated (unless actually teared-off).

- Add support for toggle state to PopupWindowController.

Change-Id: I60e004e6ada3efe092352cb93be5aae346073f83
Reviewed-on: https://gerrit.libreoffice.org/40557Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Maxim Monastirsky <momonasmon@gmail.com>