test: add unit tests for crons_monitor_data

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (ea40479) 25.59% compared to head (534afad) 29.61%. Report is 1 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #79 +/- ## ========================================== + Coverage 25.59% 29.61% +4.02% ========================================== Files 22 22 Lines 1633 1651 +18 ========================================== + Hits 418 489 +71 + Misses 1175 1115 -60 - Partials 40 47 +7 ```

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