Automatic merge from submit-queue
kubeadm: Centralize commonly used paths/constants to the constants pkg
**What this PR does / why we need it**:
Before there were constants defined for the control plane components in three different places:
- images
- phases/controlplane
- phases/selfhosting
Now they are in one centralized place. I also moved funcs for building common paths to that lib.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
Dependency for: https://github.com/kubernetes/kubernetes/pull/48899
**Special notes for your reviewer**:
Most of this PR really is autogenerated with a replace tool. I tested this and things work just normally as well.
**Release note**:
```release-note
NONE
```
@timothysc @dmmcquay @pipejakob @kubernetes/sig-cluster-lifecycle-pr-reviews
