Add text labels to groups of icons on module selection toolbar
The module icons shown on the module selection toolbar are grouped into sections based on the modules' category tags. To improve usability of the toolbar and ease module selection we should add the relevant category tag as a text label for each group of icons.
This will require modification of the WorkBench class, which is in pickcells-container in the pickcells-essentials repo.
Modifications should be done on a fork of the "develop" branch