northbound: refactor infrastructure for operational-data retrieval #199

All 374 tests pass, 2 skipped in 0s

    1 files ±0   15 suites ±0 0s ⏱️ ±0s
376 tests ±0 374 ✔️ ±0 2 💤 ±0 0 ❌ ±0
380 runs ±0 378 ✔️ ±0 2 💤 ±0 0 ❌ ±0

Results for commit 9968094. ± Comparison against earlier commit e4ddd47.