tdf#128230 Require password if the Unprotect button is visible

Regression from commit a2279bb2f52ee5bbe8d38433aac55aa1a16661fb

Before that requiring password depended on the current text of
the Protect/Unprotect button, which was changed dynamically.

This commit changed that logic and introduced two buttons in the
new .ui file that are hidden/shown dynamically.

The password condition however was changed to check the visibility
of the new Protect button instead of the Unprotect button.

Change-Id: Ie24e1b2d45fa92a375a29b7bc71689f9b83ae9dc
Reviewed-on: https://gerrit.libreoffice.org/81310
Reviewed-by: Michael Stahl <michael.stahl@cib.de>
Tested-by: Jenkins
diff --git a/sfx2/source/dialog/securitypage.cxx b/sfx2/source/dialog/securitypage.cxx
index fcafc16..8dcc830 100644
--- a/sfx2/source/dialog/securitypage.cxx
+++ b/sfx2/source/dialog/securitypage.cxx
@@ -331,7 +331,7 @@ IMPL_LINK_NOARG(SfxSecurityPage_Impl, RecordChangesCBToggleHdl, weld::ToggleButt
    }

    const bool bNeedPasssword = !m_bOrigPasswordIsConfirmed
            && m_xProtectPB->get_visible();
            && m_xUnProtectPB->get_visible(); // tdf#128230 Require password if the Unprotect button is visible
    if (!bAlreadyDone && bNeedPasssword)
    {
        OUString aPasswordText;