Add visible switch to GUI for map switcher layer list component
Apply formatting.
Issue #58: Enable/Disable applicable TOC options based on visibility.
Merge branch '#58/add-map-switcher-toc-visibility-toggle' into develop
Issue #57: Support including items from 'My Content' by double-clicking.
Remove unused imports.
Issue #57: Clean up interfaces used to update/dispatch layer selection/inclusion.
Merge branch '#57/include-my-content-items-by-double-clicking' into develop