Fix text-input Chinese input

[qingyiwebt]

Now IME is allowed for the window winit created, and the text input can handle the ImeCommit event,
BUT the render issue when there is CJK text in the text-input still exists.

[qingyiwebt]

https://github.com/user-attachments/assets/c4817d51-a3d8-45d4-a9da-c410d5169976

[dzhou121]

We probably should call set_ime_allowed(true) when text input is in focus, and set_ime_allowed(false) when it's out of focus.

https://github.com/lapce/floem/blob/main/src/action.rs#L213

And call set_ime_cursor_area to put the IME candidate box.

[qingyiwebt]

Ok, I will try to solve it tomorrow.

[qingyiwebt]

The calling of set_ime_cursor_area and some fixes is also added in the commit enable IME when text-input focused

[qingyiwebt]

Now text-input should work better with CJK characters and IME, the text overflow problem and cursor position should be fixed too.

https://github.com/user-attachments/assets/ec1e8ce6-9d4d-4517-9c5b-bb8958eda4f1