Let Global shortcuts run while typing, except keys that edit text (#16558)

#16505 skipped every Global shortcut while ImGui had the keyboard, so
Ctrl+S, Ctrl+R and the others did nothing while the cursor was in the
text tool's box. Skip only the chords that edit text, and only while a
text field (a wx text entry, a spin control, a web view, or an active
ImGui InputText) has the focus. Skip every Global shortcut while an
ImGui modal is open on the focused canvas.

KeyChord::edits_text() defines the text-editing chords. The Global page
of the shortcuts dialog no longer says these shortcuts apply while
typing.

docs/HLSD/keyboard-shortcuts.md

@@ -53,6 +53,13 @@ Space counts as typing. The speed dial's default is the one bare Space, and
 `MainFrame` leaves it to a focused control that uses Space itself (text fields, buttons,
 combo boxes), so it opens the dial from the canvases and the tab strip only.
 
+`MainFrame::handle_global_shortcut` skips a chord that `KeyChord::edits_text()` reports
+while a text field has the focus (a wx text entry, spin control, web view or ImGui
+InputText), and skips every chord while an ImGui modal is open, as a wx modal dialog
+would. `ImGuiWrapper::owns_key()` reads the active InputText and the popup stack
+directly, since `WantCaptureKeyboard` lags a frame, and is called only when the focus is on
+a visible canvas from `OpenGLManager::create_wxglcanvas()`.
+
 ## Which event a chord matches
 
 Letters, digits and special keys match on `wxEVT_KEY_DOWN`. Its key codes do not depend