input method popup is not shown with text input v1 clients

[lilydjwg]

Describe the bug

I can use fcitx5 to input into Chrome / Qt6 apps now, but the popup doesn't appear.

To Reproduce Steps to reproduce the behavior:

1. Enable plugin input-method-v1
2. Run fcitx5
3. Run env -u QT_IM_MODULE telegram-desktop or env -u QT_IM_MODULE wireshark or /opt/google/chrome/google-chrome --ozone-platform-hint=auto --enable-wayland-ime
4. Activate input method and type
5. Preedit text appears and text can be committed successfully, but no im popup is shown.

Expected behavior The popup appears.

Wayfire version git.

[ammen99]

We will need to add more methods/signals to the input method relay interfaces class, so that the input method popup v3 class doesn't actually depend on the ti-v3 struct (it is currently needed to get the focused surface and the cursor rectangle, the same info is available in ti-v1, but we need to define a common interface).