Initial development of PARADISE-24 task

[martinburchell]

Also contains #245, #244 and #241

I've not yet included the XML file with the full text. I'm assuming that given the measure is an attachment to https://doi.org/10.1371/journal.pone.0132410 which is published under a Creative Commons Attribution Licence,we can make it fully available.

Checklist for new tasks:

• [X] Add task to relevant menus
• [X] Generate code documentation
• [X] Update docs/source/changelog.rst
• [X] Test documentation rebuilds without errors
• [X] If the text of the task cannot be submitted here for copyright reasons, there is a template XML file under server/camcops_server/extra_string_templates.

Please [X] all the boxes above that apply

[RudolfCardinal]

Great; thank you! Yes, I agree - promoted to full availability. It is clearly stated to be open access and unrestricted use with attribution.