Fix temporal ITs to only generate DST-safe time
Fix temporal ITs to only generate DST-safe time

Randomized tests for `DateTime` Cypher type generate random date-time
values with time zone (either offset or id). They used to be flaky
because sometimes generated instant was invalid. Such instant pointed
to a non-existing time during a Daylight Saving Time adjustment/jump.
Such time values are adjusted to the nearest valid value by the
database. This made tests fail because received value was different
from the sent value.

This commit fixes the problem by making random `DateTime` generator
never generate hour of the day that is in the DST adjustment range. It
also reduces the number of test time zones to couple popular ones. This
is done to make sure all tested time zones are supported by the JVM,
neo4j database is running on.

neo4j/neo4j-javascript-driver,neo4j/neo4j-javascript-driver,neo4j/neo4j-javascript-driver,neo4j/neo4j-javascript-driver,neo4j/neo4j-javascript-driver