Automatic merge from submit-queue (batch tested with PRs 41921, 41695, 42139, 42090, 41949)
AWS: Support shared tag `kubernetes.io/cluster/<clusterid>`
We recognize an additional cluster tag:
kubernetes.io/cluster/<clusterid>
This now allows us to share resources, in particular subnets.
In addition, the value is used to track ownership/lifecycle. When we
create objects, we record the value as "owned".
We also refactor out tags into its own file & class, as we are touching
most of these functions anyway.
```release-note
AWS: Support shared tag `kubernetes.io/cluster/<clusterid>`
```