strict_date_optional_time changes to have optional minute part.
It already allowed optional second and fraction of second part.
This allows parsing 2018-01-01T00+01 , 2018-01-01T00:00+01 , 2018-01-01T00:00:00+01 , 2018-01-01T00:00:00.000+01
It won't allow parsing a timezone without an hour part as this is not allowed by iso8601 spec

closes #49351

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