Fix new problems with VR plugin

[edreamleo]

PR #3893 was a first draft. This issue continues the work on the new VR plugin.

Thomas (in the old PR) reports the following:

vr-toggle does that thing where the VR pane is created but hidden. After that issuing vr-show does display a normal-sized VR pane to the right of the body pane.

However, after closing the Leo window I got this error message, and it took a long time for the shutdown to complete:

QFontDatabase: Must construct a QGuiApplication before accessing QFontDatabase

Issuing vr-show first acted just like vr-toggle.

Leo 6.7.9-devel, ekr-3892-vr-pane branch, build 8ede3fc77e
2024-05-14 05:12:23 -0500

[edreamleo]

@tbpassin I am going to close this issue. It's probably obsolete or already fixed.

Please create a new issue for any further problems with the VR plugin.