kore simplification logs not using rule labels

[jberthold]

The simplification logs contain rule labels if they exist, or otherwise rule locations, to relate rule IDs to K source code (labels or locations) .
The log lines have shape {context: [..., simplification: <rule hash>, detail], message: <rule label or location>}.

While booster uses rule labels if they exist, simplification logs from kore do not report labels and always use locations. Kore should log the rule label if a rule has a label.