Massively reorganize and clean up the whole Rust codebase (#478)

* Massively reorganize and clean up the whole Rust codebase

* Additional changes during code review

editor/src/viewport_tools/tools/crop.rs

@@ -0,0 +1,22 @@
+use crate::message_prelude::*;
+use crate::viewport_tools::tool::ToolActionHandlerData;
+
+use serde::{Deserialize, Serialize};
+
+#[derive(Default)]
+pub struct Crop;
+
+#[remain::sorted]
+#[impl_message(Message, ToolMessage, Crop)]
+#[derive(PartialEq, Clone, Debug, Hash, Serialize, Deserialize)]
+pub enum CropMessage {
+	MouseMove,
+}
+
+impl<'a> MessageHandler<ToolMessage, ToolActionHandlerData<'a>> for Crop {
+	fn process_action(&mut self, action: ToolMessage, data: ToolActionHandlerData<'a>, responses: &mut VecDeque<Message>) {
+		todo!("{}::handle_input {:?} {:?} {:?} ", module_path!(), action, data, responses);
+	}
+
+	advertise_actions!();
+}