Add missing exposed methods

Author: sfe-efficy

src/components/BDropdown/BDropdown.vue

@@ -196,4 +196,8 @@ onMounted((): void => {
     },
   })
 })
+
+defineExpose({
+  hide,
+})
 </script>

src/components/BFormSelect/BFormSelect.vue

@@ -169,4 +169,9 @@ const blur = () => {
   }
 }
 // /methods
+
+defineExpose({
+  blur,
+  focus,
+})
 </script>