Chore(internal): Refactor const usage and unready info message

[Baarsgaard]

Cleaned up some const declarations used across different controllers but scattered around.

[theSuess]

Since you're already touching all the return paths, can you adapt this to remove the requeueAfter in the error case? It is ignored and causes an ugly error log message:

2025-01-10T11:58:47.418+0100    info    Warning: Reconciler returned both a non-zero result and a non-nil error. The result will always be ignored if the error is non-nil and the non-nil error causes reqeueuing with exponential backoff. For more details, see: https://pkg.go.dev/sigs.k8s.io/controller-runtime/pkg/reconcile#Reconciler

[Baarsgaard]

I was planning to refactor one reconcile function per PR as you can see in:
#1807 #1814 #1815
Where I fix the warnings as well as twice logged errors.
But if you prefer, I can do just the warnings here @theSuess?
This did not change any behaviour which is why I opted to keep it separate.

[Baarsgaard]

Update: I decided to follow through with my plan as this meant I would reduce merge conflicts among my PRs as well.
This means I changed RequeueDelay back to being capitalised and public for now.