[tesseract-explorer] add 3rd level to SelectCube interface

[davelandry]

Currently, the annotations that are used to determine the first and second selectors in SelectCube.jsx are topic and subtopic.

In the case where multiple cubes have identical topic and subtopic annotations, we need a 3rd selector that allows users to switch between the available cubes. An example of this is the OEC, where the following hierarchy is desired:

• International (topic)
  • Trade (subtopic)
    • trade_i_baci_a_92 (cube)
    • trade_i_baci_a_96 (cube)
    • trade_i_baci_a_02 (cube)
    • trade_i_baci_a_07 (cube)
    • trade_i_baci_a_12 (cube)
    • trade_i_baci_a_17 (cube)

Here are some specific behaviors that we need to catch for this new 3rd dropdown:

• [x] use the table annotation if available, otherwise just show the cube name
• [ ] auto-select the first cube in the list (default sort should just be a simple A-Z alpha-sort)
• [ ] add a prop that allows users to provide a custom sort function for this list (cubeSort?)
• [ ] add a prop that allows users to override the default cube selectionr (cubeDefault?)

[davelandry]

@frabarz I'm okay closing this for now, and revisiting the sorting stuff if the need arises

[frabarz]

I'm also experimenting with the use of context + hooks to better distribute these additional config params, the useTranslation hook gave me some ideas.