Consider options to indicate location of EFG areas not visible on world view

[tmfrnz]

Some EFG areas are very small and not or hardly visible when zoomed out, i.e. when viewing the whole world.

Example EFGs are

• MFT1.2
  
• MFT1.3
  

To limit the risk of users missing this information, it would be good to consider options optionally indicate the locations of these small EFG areas

[tmfrnz]

Here a couple of options that come to mind:

1. allow optionally specifying and multiple (rectangular) boxes that are overlaid (on low zoom levels) and could also offer a click-to-zoom function
   
2. allow optionally specifying an additional vector layer containing large enough buffers (could again offer a click-to-zoom function)
   

both graphics are mock-ups only for illustrative purposes and do not reflect actual locations

The benefit of the 2nd options would be that the process of identifying these "areas of interest" could be automated

[tmfrnz]

@sylvhay @jrfep suggest that these areas should not be shown when in Analyse? Otherwise we may want to consider using different colours.

[tmfrnz]

@sylvhay removed these highlights in "Analyse" for now... but let me know if you prefer otherwise

[sylvhay]

Thanks, that makes sense to me