Switching image display inspector section to declarative UI

[KRLango]

Part of #1093

[cmeyer]

This looks ok - but I'm wondering whether you could replace the other use of make_display_type_chooser in LinePlotDisplayInspectorSection at the same time? You don't have to fully convert LinePlotDisplayInspectorSection - just that individual item. I didn't look closely - is there a reason not to do that right now?

Also made a few whitespace comments - there should be two blank lines before top level classes and functions.

[KRLango]

The reason I didn't change the LinePlotDisplayInspectorSection to use the make_display_type_chooser was to keep this PR focused on just the 1 section of the inspector. My plan was to do the LinePlotDisplayInspectorSection after this PR was accepted using that function and clean up the (then unused) old method at that point.