dillon1000/react

🌲 Separate pass for lowering reactive scopes

For Forest, we previously converted reactive scopes into derived signals during 
Codegen. I'm moving this to a separate pass primarily to keep codegen simple 
since there's enough complexity just dealing with core JS semantics. Ideally 
we'd do a similar setup even for regular Forget, ie lower reactive scopes just 
prior to codegen. 

At the same time i also reordered the forget passes to be just before codegen, 
and cleaned things up a bit. For state lowering, we now just rewrite `useState` 
-> `createState`, because we actually need to keep around the setter function to 
trigger scheduling updates in addition to writing the signal value.