This PR merges the `quick_action_bar` crate into the `zed` crate.
We weren't really gaining anything by having it be a separate crate, and
it was introducing an additional step in the dependency graph that was
getting in the way.
It's only ~850 LOC, so the impact on the compilation speed of the `zed`
crate itself is negligible.
Release Notes:
- N/A
Marshall Bowers
e0245b3f30