Create new API and CLI default test suites and helpers for Codeception

[shadyvb]

From https://github.com/humanmade/product-dev/issues/848

We discussed having two additional test suites defined for the convenience of engineers, which will be geared towards API, and CLI tests.

This includes setting up new test suites, using respective available modules/helpers from wp-browser eg. WPCLI, and making them available to the bootstrap sub-command so they're created by default unless otherwise specified.

[rmccue]

With the latest changes and tools we're now providing, this may be as easy as adding a small new file. Additionally, our wp-cli loader doesn't load every part of wp-cli, only the core of it, so we may need to change this or support additional ways to load things (haven't seen anything in the docs for it).