Support for layers in Draw

[nuokh]

From: https://github.com/nextcloud/richdocuments/issues/2317#issuecomment-1194486126

Is your feature request related to a problem? Please describe. I want to create process maps in LibreOffice Draw using swimlanes. I can create a new layer and lock it in the desktop version of LibreOffice Draw. However, Nextcloud Office doesn't seem to offer any layer functionality to create, order, lock or edit layers.

Describe the solution you'd like I would like to create, order, lock and edit layers in diagrams.

Describe alternatives you've considered I work around this by creating the layers in LibreOffice Draw "offline" and then upload the .odg file. As soon as I need to do something with these layers I have to download the .odg file, edit it and reupload. Using the Nextcloud sync client would help but it blocks real time collaboration as soon as we need layers.

[Ezinnem]

@pedropintosilva