Adds nice-plug-slint, the official nice-plug Editor integration for Slint
UIs, addressing #39. Follows the same shape as nice-plug-egui /
nice-plug-iced: a thin glue crate over a generic *-baseview windowing crate
(here, the new slint-baseview — see its companion PR).
API:
SlintEditor::new(state, || MyComponent::new())
.with_setup(|handler, window| { ... })
.with_event_loop(|handler, setter, window| { ... })
SlintEditorState is persistable via #[persist] for save/restore of the
editor size; the per-frame Handler gives access to the component, the Slint
window, the GuiContext, parameter setters, and resize control.
This upstreams my third-party adapter, split so the reusable Slint<->baseview
windowing is in slint-baseview and only the nice-plug-specific glue is here.
Dependency note: nice-plug-slint depends on slint-baseview via a git
dependency until slint-baseview is published to crates.io; switch to a version
dep at that point. (A gain_slint example mirroring gain_egui is a natural
follow-up.)