feat(textarea): add ionic theme design with medium size (#29776)

- Adds the typography styles for the default size (medium)
- Adds the styles for the outline fill 
- Adds the styles for the label & helper text
- Adds the spacing for the label, textarea, counter and helper text

packages/vue/src/proxies.ts

@@ -858,6 +858,7 @@ export const IonTextarea = /*@__PURE__*/ defineContainer<JSX.IonTextarea, JSX.Io
   'label',
   'labelPlacement',
   'shape',
+  'size',
   'ionChange',
   'ionInput',
   'ionBlur',