The glimmerjs/glimmer.js monorepo is littered with
"standalone Glimmer.js" functionality that we
don't use and that is not being maintained. But it
also contains two packages that are critical to
ember: `@glimmer/component` and
`@glimmer/tracking`.

I want to bring both of those packages into here
instead, while jettisoning their extra complexity
that exists only to make them portable to the
"standalone Glimmer.js" use case.

This PR brings over @glimmer/component, and simplifies it by:
 - dropping support for Ember < 3.13.
 - converting to a v2 addon

This also adds end-to-end test coverage exercising
an interactive glimmer component.

valid v2 addon

expanding end-to-end test coverage to exercise glimmer component and glimmer tracking