fix(event-display): fix track 'Color by' when loading JSON with linke…

[valponce]

How to reproduce the bug :

• Phoenix is launched on the LHCb project, loading default JSON data that does not have linked tracks.
• A second JSON file containing linked tracks is loaded right after (selectedEvents.json)
• The "Color by: Vertex" option for the tracks stopped working.

Issue :
When loading the new JSON file, a new Phoenix menu node is created based on the new data and compared against the previous menu node (see loadStateFromJSON() in phoenix-menu-node.ts). For each configuration with the same label and type, the previous configuration's properties are kept, except for the property options, where the new one is adopted.
Consequently, for the "Color by" configuration (created in color-options.ts), the old version of the onChange function was retained instead of using the new one. However, this function relies on the colorByOptions attribute, which did not contain a "Vertex" option during the initial load since the data lacked linked tracks. Therefore, when switching "Color by" to Vertex in the new load, nothing happens.

Fix :
Keep not only the property options, but also the property onChange.