Improve dry run log accuracy

[tomzx]

While testing pod-reaper in dry run, one issue we observed when numerous pods would match the rules defined and MAX_PODS is defined is that all the matching pods would be marked as pod would be reaped but pod-reaper is in dry-run mode.

Our expectation in this case would have been that we would see MAX_PODS pods marked as can reap, while the remainder would be marked aspod would be reaped but maxPods is exceeded (possibly also indicating pod-reaper is in dry-run mode). This would better reflect the non dry run behavior (i.e., reaping at most MAX_PODS pods) and would appear safer if dry run was turned off.

A simple approach to solve this issue would be to log/indicate that we're in dry run mode on start, and keep all subsequent log output just as if it was a live run, simply not executing the reaping process.