allow for logging customization

[nabuskey]

As mentioned in #15, currently it's not possible to configure logging format or level.

This PR ensures logging customization work and implements our own defaults: RFC3339 timestamps and console logs.
Uses slog as the underlying implementation.

[cmoulliard]

Ideally we should use the new go logger - #15 (comment) ;-) @nabuskey

[nabuskey]

I know. I was trying to use slog first but our controller-runtime is too old and doesn't come with a version of logr that supports slog. #95 needs to be resolved first. At least this PR makes it possible to change logging configuration...

[nimakaviani]

LGTM.

if we pull in the new Argo types repo that @greghaynes created, shall we be able to update controller-runtime and use the newer logr instead?

[nabuskey]

Yes. We should be able to do that.

[nabuskey]

This PR now uses slog as the underlying logging implementation for controllers.

[cmoulliard]

That looks better using ./idpbuilder create -l debug

time=2024-02-14T12:45:51.076+01:00 level=INFO msg="Starting EventSource" controller=custompackage controllerGroup=idpbuilder.cnoe.io controllerKind=CustomPackage source="kind source: *v1alpha1.CustomPackage"
time=2024-02-14T12:45:51.076+01:00 level=INFO msg="Starting Controller" controller=custompackage controllerGroup=idpbuilder.cnoe.io controllerKind=CustomPackage
t

Remarks - see: #15 (comment):

• We should review the format of the time as it is still a bit too long 2024-02-14T12:45:51.076+01:00

	customTimeEncoder := func(t time.Time, enc zapcore.PrimitiveArrayEncoder) {
		enc.AppendString(t.Format("2006-01-02 15:04:05.000"))
	}

• What about showing colors EncodeLevel: zapcore.CapitalColorLevelEncoder, ?
• Log fields should be removed time=, level=, msg=

2024-02-14 12:45:51.076 INFO custompackage controllerGroup=idpbuilder.cnoe.io controllerKind=CustomPackage source="kind source: *v1alpha1.CustomPackage"
...

[nabuskey]

Let's worry about formats and coloring and what not later. Like I mentioned, this is meant to allow for actual customization of logs. Right now, we have NO control over log levels or formats.

[greghaynes]

Can we make a good-first-issue for improving this logging as we mention? I think this PR is good to merge as is, but I'd like to not lose that issue if possible.