Run CI on PRs, fix lint + ts

.github/workflows/nodejs.yml

 name: Node CI
 
-on: push
+on: [push, pull_request]
 
 jobs:
   build:

src/NativeSafeAreaView.web.tsx

         paddingBottom,
         paddingLeft,
         paddingRight,
-      } = getComputedStyle(element);
+      } = window.getComputedStyle(element);
 
       const insets = {
         top: paddingTop ? parseInt(paddingTop, 10) : 0,

tsconfig.json

     "module": "commonjs",
     "strict": true,
     "moduleResolution": "node",
+    "skipLibCheck": true,
     "lib": ["dom", "es2015", "es2016", "esnext"],
     "jsx": "react-native"
   },