[wayland] Implement zwp_text_input to make onscreen keyboard work with QT apps
Feature summary
In GTK3/4 apps, the builtin onscreen keyboard pops up when touching an input field. This should also be made work with QT (and possibly other) apps.
How would you like it to work
Implement wayland protocols used by QT and others. Relevant interfaces: wl_text_input, zwp_text_input_v2
Relevant links, screenshots, screencasts etc.
Like this for KDE: https://phabricator.kde.org/D1631