* Introduce `NewContext`, deprecate `NewImplFull`.
Our generated `NewImpl` methods have long taken `context.Context`, but despite many iterations the forms we expose from our `controller` package never have. This change contains several elements:
1. Expose a new `NewContext` method that takes `context.Context` in addition to the current `NewImplFull` signature.
2. Call `NewContext` instead of the deprecated `NewImpl` from our generated controller code.
3. Call `NewContext` from all our webhook reconcilers.
* Add a Tracker to controller.Impl to cut down on downstream boilerplate.
* Create a new singleton Reconciler for the webhook secret.
This change creates a new Reconciler (not yet hooked up) that ensures that the
webhook secret has the appropriate shape. I call this a "singleton Reconciler"
because this reconciler exists to effectively reconcile a single resource, which
will be a pattern for the webhook's reconcilers.
* Address linter problems