FEAT #13983 TIME 1:15 fix hide left side nav in signature when editor exits fullscreen

migration/20.10/2010.sql

sql/data_en.sql

sql/data_fr.sql

sql/structure.sql

src/app/user/controllers/UserController.php

src/frontend/app/signature-book.component.html

src/frontend/app/viewer/document-viewer.component.html

src/frontend/app/viewer/document-viewer.component.ts

...ins/collabora-online/collabora-online-viewer.component.ts

.../plugins/onlyoffice-api-js/onlyoffice-viewer.component.ts