feat(VSnackbar): pass internal isActive model through activator slot

this is in line with how VOverlay does it

packages/vuetify/src/components/VSnackbar/VSnackbar.tsx

@@ -21,10 +21,13 @@ import { genOverlays, makeVariantProps, useVariant } from '@/composables/variant
 import { mergeProps, nextTick, onMounted, onScopeDispose, ref, shallowRef, watch } from 'vue'
 import { genericComponent, omit, propsFactory, refElement, useRender } from '@/util'
 
+// Types
+import type { Ref } from 'vue'
+
 type VSnackbarSlots = {
  activator: { isActive: boolean, props: Record<string, any> }
  default: never
- actions: never
+ actions: { isActive: Ref<boolean> }
  text: never
 }
 
@@ -227,7 +230,7 @@ export const VSnackbar = genericComponent<VSnackbarSlots>()({
  }}
  >
  <div class="v-snackbar__actions">
- { slots.actions() }
+ { slots.actions({ isActive }) }
  </div>
  </VDefaultsProvider>
  )}