Layout system implementation and applied to tool options bar (#499)

* initial layout system with tool options

* cargo fmt

* cargo fmt again

* document bar defined on the backend

* cargo fmt

* removed RC<RefCell>

* cargo fmt

* - fix increment behavior
- removed hashmap from layout message handler
- removed no op message from layoutMessage

* cargo fmt

* only send documentBar when zoom or rotation is updated

* ctrl-0 changes zoom properly

* Code review changes

Co-authored-by: Keavon Chambers <keavon@keavon.com>

editor/src/communication/message.rs

@@ -31,6 +31,8 @@ pub enum Message {
 	#[child]
 	InputPreprocessor(InputPreprocessorMessage),
 	#[child]
+	Layout(LayoutMessage),
+	#[child]
 	Portfolio(PortfolioMessage),
 	#[child]
 	Tool(ToolMessage),