SAM plugin contraints on dates, tidy up

[bobular]

Two things

• add shape = (ordinal OR continuous) constraints to

  service-eda/src/main/java/org/veupathdb/service/eda/data/plugin/standalonemap/FloatingTimeSeriesPlugin.java

  Line 33 in e18849d

  .temporal(true)

  (and also its collections sibling?)
• add a new pattern (I think) for temporal number variables for the new timeline histogram:

  service-eda/src/main/java/org/veupathdb/service/eda/data/plugin/standalonemap/FloatingDateHistogramPlugin.java

  Line 49 in e18849d

  .types(APIVariableType.DATE)