Bugfix/hidden workspace

[fsih]

The basics

• I branched from develop
• My pull request is against develop
• My code follows the style guide

Finish up #1819 by adding a TODO comment

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[fsih]

I signed it!

[googlebot]

CLAs look good, thanks!

[AnmAtAnm]

Make this @private isVisible_, adding getVisibility() to discourage workspace.isVisible = false;.

[fsih]

done