Clean up a bit the interface

[Jo-Schie]

I think the application would look nicer if the buttons "Reset Map" and "Download Geojson" as well as the "Example file" where placed next to the "Browse" button on top. It would be also nice if they where all styled in a similar way using e.g. the existing button style of the "Reset Map" button (blue with white background). Probably the best order would be "Browse" "Example File" "Reset Map" "Download Geojson".

Also i think it would be more logical and recognizable for people to call the tool "Project Location Validator" because the model is called "Open Project Location Model" and not "Open Geodata Model".