The one with `enterprise` support in m2-playground

To support enterprise projects in the m2-playground, 2 changes needed to happen

1. introduce a new flag -e to instruct wf2 to setup an enterprise project
2. allow public/private keys to be used once, but not override existing ones

Since most developers will have there own personal public & private keys saved in wf2, we needed to allow a one-time set of keys to be used, but to NOT override your personal ones.

wf2 m2-playground 2.3.4 --username 123456 --password 654321 -e