Update to 0.76

[chrisglein]

Main change here is to create a new app from template on 76 and bring the app logic over.

This causes this to be hit: facebook/react-native#46355
As manifested by this error:

 ERROR  SyntaxError: D:\GitHub\artificial-chat2\node_modules\react-native-windows\Libraries\vendor\emitter\EventEmitter.js: Unexpected token, expected "]" (39:5)

  37 |
  38 | type Registry<TEventToArgsMap: {...}> = {
> 39 |   [K in keyof TEventToArgsMap]: Set<Registration<TEventToArgsMap[K]>>,
     |      ^
  40 | };
  41 |
  42 | /**

That can be mitigated by removing the babel.config.js changes, but that brings back this: microsoft/fluentui-react-native#1891
As manifested by this error (release builds only):

- Build failed with message EXEC : error node_modules\@fluentui-react-native\checkbox\lib-commonjs\Checkbox.js: D:\a\artificial-chat\artificial-chat\node_modules\@fluentui-react-native\checkbox\lib-commonjs\Checkbox.js: pragma and pragmaFrag cannot be set when runtime is automatic. [D:\a\artificial-chat\artificial-chat\windows\artificialChat\artificialChat.vcxproj]. Check your build configuration.

So... what to do? Either figure out the compatible version of useTransformReactJSXExperimental with the 0.76 Flow issues. Or go back and patch fluentui-react-native to not have those issues in release builds.