[Typescript] Step1 & 2 for converting a js app to ts

1. Compiling in "loose mode"

Start with all tests passing
Rename all .js to .ts, allowing implicit any
Fix only things that are not type-checking, or causing compile errors
Be careful to avoid changing behavior of function
Get test passing again.

# rename all JSX files in src/ to TSX
find src -name '*.jsx' -exec bash -c 'git mv "$0" "${0%.jsx}.tsx"' "{}" \;
# rename all JS files in src/ to TS
find src -name '*.js' -exec bash -c 'git mv "$0" "${0%.js}.ts"' "{}" \;
# rename all JSX files in src/ to TSX
find tests -name '*.jsx' -exec bash -c 'git mv "$0" "${0%.jsx}.tsx"' "{}" \;
# rename all JSX files in src/ to TSX
find tests -name '*.jsx.snap' -exec bash -c 'git mv "$0" "${0%.jsx.snap}.tsx.snap"' "{}" \;
# rename all JS files in tests/ to TS
find tests -name '*.js' -exec bash -c 'git mv "$0" "${0%.js}.ts"' "{}" \;

and don't forget to make this small change to index.html

```diff
--- a/index.html
+++ b/index.html
@@ -8,6 +8,6 @@
   </head>
   <body class="font-sans antialiased h-screen">
     <div id="appContainer" class="w-full h-full"></div>
-    <script src="src/index.js" type="text/javascript"></script>
+    <script src="src/index.ts" type="text/javascript"></script>
   </body>
 </html>
```

and this change to tsconfig for step 1.

2. Explicit Any

Start with tests passing
Ban implicit any

"noImplicityAny": true,

Where possible, provide a specific and appropriate type
- Import types for dependencies from DefinitelyTypes
- otherwise explicit any
Get tests passing again

```diff
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -3,9 +3,10 @@
     "target": "ES2018",
     "allowJs": true,
     "module": "commonjs" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */,
-    "strict": true /* Enable all strict type-checking options. */,
+    // "strict": true /* Enable all strict type-checking options. */,
     "forceConsistentCasingInFileNames": true,
     "noEmit": true,
+    "noImplicitAny": false,
     "outDir": "dist",
     "declaration": true,
     "jsx": "react",
```