1156 validate temporal

[janette]

User story

As a data publisher I want to be alerted when the temporal value is not valid.

$d1 = '2000-01-15T00:45:00Z'; //valid
$d2 = '2000-01-01T01:00:00+1200'; //valid
$d3 = '1988-12'; //valid
$d4 = '01/01/2015-12/31/2019'; //not valid
$d5 = '2007- present'; //not valid
$d6 = '2000-01-15T00:45:00Z/2010-01-15T00:06:00Z'; //valid
$d7 = '2000-01-15T00:45:00Z/P1W'; //valid

How to reproduce

Harvest from https://data.chhs.ca.gov/data.json

Errors

see https://github.com/NuCivic/healthdata/issues/1156

Error: Call to a member function getTimestamp() on null in DatajsonHarvestMigration->prepareRow() (line 207 of ..../dkan/modules/dkan/dkan_harvest/modules/dkan_harvest_datajson/dkan_harvest_datajson.migrate.inc)

Behavior

Now when harvesting any temporal value that is not valid will NOT be included in the dataset, that "field" will be empty, and an error message will be logged in the harvest error dashboard.

Reminders

• There is test for the issue.
• Coding standards checked.
• Review docs.getdkan.com (or in /docs) to see if it still covers the scope of the PR and update if needed.