Prints should be able to include a legend

[Grammostola]

Is your feature request related to a problem? Please describe.
The print control incorporates no map legend in the printed pdf/image and this hinders what kind of prints can reasonably be interpreted without ambiguity

Describe the solution you'd like
A limited legend in the print layout

Describe alternatives you've considered
Endless legend on additional pages

Additional context
Map legend layouts on prints can be the subject of some debate as they are almost always a compromise of some sort. Also for Origo there is a need for it to work with several types of layers/services.