The default ShardingTest verbosity is currently zero, but we have many
tests, which bump it to 1 and even higher.
Since verbosity level of 0 is sometimes insufficient for investigating
transient failures, this change makes the default to be 1 and removes all
places, which explicitly make it 1 or higher.
No functional changes, just converting everything to use the JSON-based
constructor.
Also moves some sharding-specific tests out of noPassthroughWithMongod and
under the sharding suite.
