Fix some typescript issues (#32586)

Fixes around 30 or so typescript errors. No runtime changes.

.eslintrc.yaml

@@ -642,7 +642,7 @@ rules:
   no-this-before-super: [2]
   no-throw-literal: [2]
   no-undef-init: [2]
-  no-undef: [2, {typeof: true}]
+  no-undef: [2, {typeof: true}] # TODO: disable this rule after tsc passes
   no-undefined: [0]
   no-underscore-dangle: [0]
   no-unexpected-multiline: [2]