Export PDF functionality

[lamby]

Expected Behavior

Pressing Export exports the page as a PDF

Current Behavior

(Not implemented)

Checklist before submitting

• I have confirmed this using the officially supported Docker Compose setup using the local.yml configuration and ensured that I built the containers again and they reflect the most recent version of the project at the HEAD commit on the master branch
• I have searched through the other currently open issues and am confident this is not a duplicate of an existing bug
• I provided a minimal code snippet or list of steps that reproduces the bug.
• I provided screenshots where appropriate
• I filled out all the relevant sections of this template

[Serhiy-Shekhovtsov]

@lamby, I can see the interface-backend tag, is there a particular reason why this has to be done on the server side? I am asking this, cause implementing it on the client side should be an easy task.

[lamby]

@Serhiy-Shekhovtsov Implementing client-side is fine :)