Add a setting for sending a notification on BEL (#20011)

## Summary of the Pull Request
Targets #20010 

Adds another `bellStyle` flag option. This sends a windows toast
notification to the user when a BEL is encountered

- [X] Closes #18605 
- [ ] Documentation updated

Heavily based on #19936 
Co-authored by @zadjii-msft

doc/cascadia/profiles.schema.json

@@ -60,7 +60,8 @@
             "enum": [
               "audible",
               "window",
-              "taskbar"
+              "taskbar",
+              "notification"
             ]
           }
         },
@@ -70,6 +71,7 @@
             "audible",
             "taskbar",
             "window",
+            "notification",
             "all",
             "none"
           ]