fdo#63020: Replace ::comphelper::stl_begin()...

And use some templates inside include/com/sun/star/uno/Sequence.hxx

Change-Id: I48875fa1517751fc4cb0cf2b6c08b88975a29b47
Reviewed-on: https://gerrit.libreoffice.org/6599
Tested-by: LibreOffice gerrit bot <gerrit@libreoffice.org>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Tested-by: Stephan Bergmann <sbergman@redhat.com>