feat: add ability to disable nonce

[dougkeen]

This is useful if you use a platform like Auth0, whose Apple token exchange flow doesn't currently support nonces.

With this change, you can disable nonces like so:

await appleAuth.performRequest({
  nonceEnabled: false,
  requestedOperation: AppleAuthRequestOperation.LOGIN,
  requestedScopes: [AppleAuthRequestScope.EMAIL, AppleAuthRequestScope.FULL_NAME],
})

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[mikehardy]

I don't see why not - I know plumbing nonce through was something everyone had to do semi-unexpectedly for it to work and caused a PR to the expo apple auth as well (firebase requires nonce, so that drove it). So I can see the need and the code looks fine to me. I'll leave for @Salakar to merge in case he knows a reason not to

[Salakar]

@dougkeen I'm happy to add this in so thanks for this PR - it does though look like you're missing nonceEnabled: true as a default value in JS; the same way requestOperation defaults, e.g.;

https://github.com/invertase/react-native-apple-authentication/blob/master/lib/AppleAuthModule.js#L60
and
https://github.com/invertase/react-native-apple-authentication/blob/master/lib/AppleAuthModule.js#L66-L72

Without this I think it will cause a native crash here: https://github.com/invertase/react-native-apple-authentication/pull/52/files#diff-c1c850227210d2e412283742bab2ec03R44 as it'd try to call isEqual on a nil value

[dougkeen]

@Salakar Good call. I definitely missed that bit in the javascript where the defaults are set and type-checked.

FYI, in Obj-C messages sent to nil simply return nil, which is probably why I didn't see any native crashes in my testing.

[mikehardy]

@Salakar I believe this is ready for merge if your concerns are addressed? (they seem to be)

[Salakar]

Thank you :)