Fixes#42444
- Changed `accepts_text_input` on the editor to be more precise.
Previously, it returned `true` only in insert mode. Now it also returns
`true` when an operator is pending.
- On Windows, we disable the IME whenever there is no input handler
which `accepts_text_input`.
- How this improves Vim mode: in insert mode, the IME is enabled; in
normal mode, it is disabled (command keys are not intercepted); when an
operator is pending, the IME is re-enabled.
Release Notes:
- On Windows, the IME is disabled in Vim normal and visual modes.