Expanded Color Mapping Options for Localization Datatypes in Annotator

[sbatchelder]

Color Mapping for Localization Bounding Box (and other Localization datatypes) is limited. A LocalizationType can only have one color associated with it. It's the active color only, and it applies to all instances of that LocalizationType.

My users would like to be able to set custom color mappings to Localizations (even of the same type) based on their attributes in order to better view and compare them in the annotator.

For instance, if two or more versions are visible at the same time, without per-version color mapping it is unclear what bboxes belong to what version, which makes comparison difficult.

Another instance, a user is working on a frame with a lot of bounding boxes with different class labels, being able to ascertain the class of a bbox by color instead of clicking on each one to verify them would be hugely beneficial.

Another instance, the user is interested in a float property of bboxes in a frame. Applying a color gradient that scales with the attribute value would be very practical.

Or this can be used to highlight certain bbox based on a boolean flag, in order to more easily spot them.

Similar to issue #1832 (Saved Filters), these color mappings should be save/loadable by the user, and a user should have the option to make their color-mapping color-filter accessible to other members of the project.