Desktop: Isolate CEF-rendered UI into separate crate and process (#4321)

* Extract CEF rendered UI into a separate process and crate

* Review

* Review

* Review

* Review

* Remove necessary workarounds

* Block on frame copy ack

* Crop and resample frames correctly

* Skip blank frames

* Fix deps

* Fix fmt

* Fix clippy warning

* Review

* Fix todo

desktop/ui/src/frames/plane.rs

@@ -0,0 +1,35 @@
+#[cfg(target_os = "linux")]
+mod linux;
+#[cfg(target_os = "linux")]
+pub(crate) use linux::*;
+
+#[cfg(target_os = "windows")]
+mod win;
+#[cfg(target_os = "windows")]
+pub(crate) use win::*;
+
+#[cfg(target_os = "macos")]
+mod mac;
+#[cfg(target_os = "macos")]
+pub(crate) use mac::*;
+
+#[cfg(any(target_os = "linux", target_os = "macos"))]
+pub(crate) enum RecvResult {
+	Frame(WireFrame),
+	WouldBlock,
+	#[cfg_attr(target_os = "macos", allow(dead_code))]
+	Closed,
+}
+
+/// Decode the wire representation of `cef_color_type_t` (its `u32` discriminant),
+/// logging unknown discriminants.
+fn wire_color_type(format: u32) -> Option<cef::sys::cef_color_type_t> {
+	match format {
+		0 => Some(cef::sys::cef_color_type_t::CEF_COLOR_TYPE_RGBA_8888),
+		1 => Some(cef::sys::cef_color_type_t::CEF_COLOR_TYPE_BGRA_8888),
+		_ => {
+			tracing::error!("Unknown color type {format} in accelerated frame");
+			None
+		}
+	}
+}