Perform screen-reader and keyboard accessibility audit

[cjcenizal]

We can refer to https://www.youtube.com/watch?v=cOmehxAU_4s for the basics to check for.

[3eif]

Accessibility Audit:

I was able to navigate through all the components fairly easy and the screen reader described to be most of what I was looking at.

A few minor issues I found:

• I can navigate through items under the Chat Inspector and Chat Setting pop up.
  
• VuiIcon component does not have alt text or aria label, screen reader just reads "image". Buttons such as Exit, Send, Inspect, and Resize button in VuiChat suffer from the same issue (related to Add label prop to VuiIconButton #111?).
• I'm not able to access or navigate to the progress bar using the screen reader
• VuiPopover does not state the amount of items in the menu like the Select component (related to Improve screen-reader accessibility of VuiPopover, VuiSearchSelect, and other popovers #113?)
• Screen reader does not shift its focus to the VuiNotification component when it appears
• No alt text for VuiSpinner

Very minor thing:

• I'm able to tab twice into the GitHub icon/button in the top right of the app header