Use Floating Action Button for buttons on map fragments

1. What is the general goal of the feature?
Currently, multiple options are displayed using AppCompatImageButtons on map fragment. Shifting to using Floating Action Button can provide a fresher look to the Geowidgets. I am attaching a wireframe and a screenshot of the app.

I used mini and normal Floating Action Buttons, and also changed the placement of the buttons a little bit.

Your views and feedback on this are welcome. :slight_smile:

This is what we started talking about here as well https://github.com/getodk/collect/issues/3202