wax accessibility improvements
- upgrade wax to 0.7.28
- close #129 (closed), #185 (closed), #186 (closed), #187 (closed), #188 (closed)
- fix issue with feedback box stealing focus every time it loads
- accessibility fixes for editor's dropdown menus/option lists and switches
- remove table column resizing feature (not usable by keyboard users)
- add role="toolbar" and aria-label to the TopMenu component
- spread collapsed toolbar buttons on the toolbar to avoid inaccessible menu dropdown
- fix alignment in editor toolbar