Add filters to the plot dialog #289

The filters should be on the original array, so if we plot a filtered array, we should be able to see other slices of the original array.

The goal is mostly to be able to plot different slices of an array just by using the scrollwheel like we can currently do with the "table" view.

Implementing #73 with "changeable filters" would make this useless because that's almost the behavior we would get from displaying arr[filter].plot() but I am beginning to doubt I will ever have the time to implement #73 properly 😢.