fdo#80490 rename AutoSpellcheck and reflect its removal from toolbar

Change-Id: If77bb61af25998e193e3e8f1ea2382fe2be4423a
Reviewed-on: https://gerrit.libreoffice.org/12498
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>