Simplify image-cleaner handling

[sgaist]

This is a follow up of #1531.

This patch refactors the creation and handling of the image cleaner daemonset.

The current behaviour makes it so that if one doesn't disable the host cleaner explicitly when using dind (or pink), they would end up with two cleaners instead of one.

The new behaviour avoids this issue by ensuring that only the container matching the selected imageBuilderType is created. Same goes for the volumes handling.

In order to have consistent naming, the "local" imageBuilderType enumeration value is replaced with "host".

It also deprecates the use of the imageCleaner.host.enabled parameter as you either want image cleanup or not.

[manics]

I've marked this as breaking since it should be considered in conjunction with #1531 so they're best treated as one larger change.

[sgaist]

One practical question for NOTES.txt: I used 0.3.0 as "breaking" version number based on the current tag list from the repository but it will likely be something else. Is there a policy with regard to that kind of value and how to manage it ?

[manics]

For this repo- not at the moment. I'm inclined to not specify the version since the current advice is to always run the latest main branch (this is what we do in https://github.com/jupyterhub/mybinder.org-deploy) so. You could perhaps link to the relevant PR(s) instead?

There's more ongoing refactoring (such as #1318 #1521) but when the repo is more stable we could consider a 1.0.0 release but that's a separate discussion!

[consideRatio]

LGTM, I added a commit changing a comment and updating syntax.