This is just a cleanup work to hide some of the private state of
ReplSetTest so it is easier to encapsulate and add new logic. Also enables
strict mode.
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.
