feat: add browser.IS_CHROMECAST_RECEIVER and class name for CSS targeting on a Chromecast receiver where Video.js is used

[misteroneill]

Description

Some people may want to use Video.js as part of their Chromecast receiver application - particularly for UI customization. This PR builds on #8676 by adding feature detection for a Chromecast receiver context.

I did not test this on a cast device as I do not own one!

Specific Changes proposed

• Add browser.IS_CHROMECAST_RECEIVER boolean
• Add vjs-device-chromecast-receiver class name for players running on a Chromecast receiver device

Requirements Checklist

• Feature implemented / Bug fixed
• If necessary, more likely in a feature request than a bug fix
  • Change has been verified in an actual browser (Chrome, Firefox, IE)
  • Unit Tests updated or fixed
  • Docs/guides updated
  • Example created (starter template on JSBin)
• Reviewed by Two Core Contributors

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 83.01%. Comparing base (ec69d5e) to head (985814a).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #8703   +/-   ##
=======================================
  Coverage   83.00%   83.01%           
=======================================
  Files         120      120           
  Lines        7996     7999    +3     
  Branches     1926     1929    +3     
=======================================
+ Hits         6637     6640    +3     
  Misses       1359     1359           

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