Project workspace should reflect that content is loading while opened and empty

[dunity]

Projects that have a "moderate" number of elements can lead to an issue present when first opening the project workspace, and seeing nothing in either column for up to a minute (could last even longer for larger projects). This could lead new users to close the workspace before any content is displayed; giving the impression of an empty/broken workspace. Some form of loading-state feedback should be displayed to the user.

At a minimum, display a tooltip upward (about 3 inches) from the center of the front-panel of the project workspace. This tooltip should read "Loading Content". This should be displayed when opening the first Project workspace in an EVR session. Display the tooltip until the content begins to present itself in the columns. Hide the tooltip when the content is finally displayed.

The most obvious case that gives rise to this issue is opening a project workspace, leaving it open, then closing EVR. Next, start a new EVR session. The issue is most apparent when the project workspace is restored upon re-entry into the new EVR session.

If you're unable to reproduce, continue to add assets to you project until the issue becomes apparent.