Eventing operator should install core things and then IMC related things

[aliok]

At the moment, eventing operator first installs the 0.10.0-imc.yaml file and then 0.10.0.yaml.
This causes some problems as the imc-dispatcher fails until the config-tracing is installed with 0.10.0.yaml. Eventually problems resolve automatically, but in my experiments it caused some unnecessary confusion.

I was originally suggest that we simply use a single file, the release.yaml file here but I saw #13.

@houshengbo I saw your ticket #13. Is it already the case that we can configure installation with or without IMC?

[houshengbo]

@aliok Not yet.
We so far decided to install IMC anyway regardless of the options, since it is another tough question we need to resolve to install operators based on configurations across both eventing and serving operators.
At this moment, I think we can use the release.yaml directly to replace both of the eventing.yaml and imc yaml.