In Helix normal mode escape runs `vim::SwitchToHelixNormalMode`, which
only switches the mode, so the diagnostic shown by `] d`, a hunk expanded
with `g o`, a hover popover and the like stayed open. Vim mode closes them
because escape there is `editor::Cancel`. Binding Helix to `Cancel` isn't
an option, since once nothing is open it collapses the selections.
Pull the part of `Editor::cancel` that runs before it touches the
selections into `Editor::dismiss_overlays`, and call it when escape is
pressed in Helix normal mode. Selections are kept as before.
Closes#55197
dualfroz
5f70e7afe2