Rename build_view to new_view and build_model to new_model

The word "new" is shorter and blends in with `new` constructors that are common
in Rust. Been meaning to do this for a while.

crates/language_selector2/src/language_selector.rs

@@ -61,7 +61,7 @@ impl LanguageSelector {
             language_registry,
         );
 
-        let picker = cx.build_view(|cx| Picker::new(delegate, cx));
+        let picker = cx.new_view(|cx| Picker::new(delegate, cx));
         Self { picker }
     }
 }