Add extractor editor property widget

[ghorwin]

Show and update property based on current extractor selection.

This property widget allows editing of extractor properties, such as:

For time-animated extractors:

• time cut index: fixed -> value; or dynamic (aligned to time slider)

For coordinate-cuts (only enable/show those that apply to the currently selected extractor):

• x-coordinate/y-coordinate/z-coordinate to cut

[ghorwin]

Duplicate of #147