CSidebar component doesn't fire 'visible-change' method correctly.

[coderkoala]

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Bug reports must include:

• Ubuntu 20.04.4 LTS
• Firefox Developer edition(105.0b7 (64-bit))
• Problematic: coreui/vue/dist/components/sidebar/CSidebar.d.ts:82
• Investigate why exactly the event doesn't dispatch payload after the menu is dismissed. This only occurs <800px, so I am certain it's a viewport issue for mobile browsers only: desktop devices face no such issues.

Since I'm working on a time sensitive project, I had to resort to disabling the visibility of the backdrop entirely, to be able to pass UAT for mobile users.

I'll get back to this issue once I'm done with my own project.