Expose API for testing dynamic plugins with Cypress

We currently have utilities functions for performing common actions in our Cypress tests (logging in, clicking nav items, etc.). We need to expose these formally as APIs that dynamic plugins can use, so each plugin doesn't need to re-implement them. The code can still live in the monorepo, but it should be published as a separate package that can be used by a plugin, similar to what we plan for the plugin SDK.

We should look at what existing static plugins are using as a starting point for the API. We'll want to get input from stakeholders on the dynamic plugin sync call.

Acceptance Criteria

• Need to determine a strategy for versioning the test API. When can we break the API? How does the package version relate to OpenShift version.
• Any public APIs should be moved into a separate package with a clear separation between public and private API.
• This story does not include actually publishing a package to npm, merely defining an API and separating the code in the repo. We will publish it as a package in a separate story.