store: add tests for recurring job scheduling

[dirkdev98]

Closes #378

/cc @tjonger it contained some bugs :S

[github-actions]

==== Benchmark result ====

Total benchmarks: 9
          Passed: 9
          Failed: 0
-----------
object validator simple      5000000  iterations     484  ns/op
object validator nested        50000  iterations   50891  ns/op
logger - strings              500000  iterations    3802  ns/op
logger - objects              500000  iterations    4679  ns/op
logger - deep objects         200000  iterations    5383  ns/op
uuid                         2000000  iterations     586  ns/op
uuid.isValid                10000000  iterations     144  ns/op
isNil                      500000000  iterations       0  ns/op
isPlainObject              100000000  iterations      19  ns/op

[github-actions]

==== C8 test coverage ====
Statements: 79.52% ( 16589/20861 )
Branches : 78.77% ( 1989 /2525 )
Functions : 74.84% ( 568 /759 )
Lines : 79.52% ( 16589 /20861 )