IME (Input Method Editor) Support

WSLg should implement IME support for CJK locale scenarios. Currently, the WSLg & WSL architecture can support existing Linux IME facilities (e.g. ibus) as tested, however, manual configuration and startup is required.

Solution
An ideal solution should reuse the Windows IME infrastructure and transport the input content to Linux window for the best experience. However, this might needs much engineering effort.

Alternative Solutions
Alternatively, WSLg can start the IME daemon and configure required environment variables (e.g. QT_IM_MODULE, IBUS_USE_PORTAL, GTK_IM_MODULE and such) without manual steps.

Additional context

• Having proper IME support is almost a must-need for CJK locale users.
• IME input flyout locations might need to be validated, but so far looks okay (60%) to me when using IBUS on WSLg. Update: Not really. Layout bug: https://github.com/microsoft/wslg/issues/8

No implementation file, test, or entry point is named. Start by reproducing the manually configured ibus setup for a CJK locale and reviewing how WSLg starts Linux desktop services. Done means CJK IME input works without manual configuration, including the required environment setup or the proposed Windows IME integration.