feat(locale): provide dir on defineLocale (#2620)

Co-authored-by: Benjamin Canac <canacb1@gmail.com>

src/runtime/types/locale.ts

@@ -1,4 +1,4 @@
-export type LocalePair = {
+export type Messages = {
   inputMenu: {
     noMatch: string
     noData: string
@@ -36,8 +36,11 @@ export type LocalePair = {
   }
 }
 
+export type Direction = 'ltr' | 'rtl'
+
 export type Locale = {
   name: string
   code: string
-  ui: LocalePair
+  dir: Direction
+  messages: Messages
 }