feat: add dock position setting

* refactor(storage.ts): move `language` and `isShowTopbar` to `setting` variable
* refactor: rename `BewSelect.vue` to `Select.vue`

src/models/models.ts

@@ -0,0 +1,5 @@
+export interface Settings {
+  language: string
+  isShowTopbar: boolean
+  dockPosition: 'left' | 'right' | 'bottom'
+}