Seperate Elev and Fuel grabbers, make `grid_grab` an aggregator.

[BadgerOnABike]

Do what I say in the title.

[BadgerOnABike]

So this is a bit different than I initially thought. Tasks below

• Allow a point and a buffer in the arguments
• All the choice of elevation or fuels to be output, default is both
• Defaults point to national layers
• Provide options for local layers
• Provide a toggle for a selector or directory