v2.3.0-beta.8

🔄 Features

• breakpoint: add global variables/mixin (#11480) (9f6f5a5), closes #6945 #9272
• VMenu: add rounded support to menu content (#11447) (ea52a89), closes #10397
• VSnackbar: add applicationable support (#11448) (6098e5f), closes #4468
• VSnackbar: add new properties and improve md2 spec (#11542) (d44b590), closes #5865 #10935