Add support for e2e testing with OAuth

[mraible]

Describe the bug

Not a bug per se, just a missing feature. In run-detox-tests.sh, there's this code:

# if oauth, only run the launch screen since you need to authenticate for entities
if [ "$JHI_AUTH_TYPE" = "oauth2" ] ; then
  rm -rf e2e/entities
fi

The entity tests don't support logging in with OIDC and are therefore unreachable. We should fix this.

Instructions To reproduce

Create a React Native app with oauth2 and detox. Then, run detox tests.

Versions (please complete the following information):

• JHipster React Native Version: main branch