feat: Emit events in PipelineReconciler

[yitsushi]

The controller itself is very simple and does not so much, most of the functionalities are living in a different codebase (like cluster queries).

This patch tries to add events on all errors, and an update even on a successful reconciliation.

Closes #3

References:

• https://github.com/weaveworks/pipeline-controller/issues/3

[yitsushi]

Extra tests about emitting event are coming soon. Requested review to get feedback if the direction is good or not.