This ensures that tests will not pass or fail based on whether the test
machine is on NZ time.
This partially reverts df050eda5d7c6ad6234d8ae7d94b46a4ddff8449, which has
already been merged. Instead of finding tests that use date calculations, we
are now setting the default time zone in SapphireTest so it will apply to the
whole test suite and any future tests.
Adjust expected values in certain tests for UTC, where the expected values had
previously been expressed in NZ time.
When creating a temp DB for test fixtures, create the DB connection with
timezone UTC.
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