feat: Added configuration to SQL Lab results "Explore" button (#10164)

* added configuration to virtual table explore button

* added description to mixin

* fixed unit tests

Co-authored-by: Jason Davis <@dropbox.com>

tests/database_api_tests.py

@@ -49,6 +49,7 @@ class DatabaseApiTests(SupersetTestCase):
             "allow_run_async",
             "allows_cost_estimate",
             "allows_subquery",
+            "allows_virtual_table_explore",
             "backend",
             "database_name",
             "expose_in_sqllab",