[SDK-3591] New Hook API supporting login and logout

[stevehobbsdev]

Changes

This PR adds a new hook useAuth0 (based on Auth0 React's hook of the same name) as an alternative to using the Auth0 class, useful for when using function components.

Example:

const onLogin = async () => {
    try {
      const credentials = await authorize({scope: 'openid profile email'});

      Alert.alert('AccessToken: ' + credentials.accessToken);
      setAccessToken(credentials.accessToken);
    } catch (e) {
      console.log(e);
    }
};

Supports:

• authorize - log in using the ULP
• clearSession - log out
• user - get the user profile
• isLoading (not currently used but here for future development when the credentials manager is added)
• error

Notes:

• The Auth0 class was moved from the index file to a different file to fix an issue with cyclic imports
• Upgrades to react@17 in dev dependencies
• Upgrades to jest@28
• API docs still to be added

Quickstart demo

https://user-images.githubusercontent.com/766403/184354283-ada855f9-fa23-4640-bfa9-c37e7f006837.mov

Testing

Unit tests have been added, as well as the API being tested using the quickstart (branch with changes).

• [X] This change adds unit test coverage
• [X] This change has been tested on the latest version of the platform/language or why not

Checklist

• [ ] I have read the Auth0 general contribution guidelines
• [ ] All existing and new tests complete without errors
• [ ] All active GitHub checks have passed