DRIVERS-2232: remove usages of currentOp and collStats from tests

[baileympearson]

Node POC: mongodb/node-mongodb-native#3638

This PR removes usage of the collStats command and currentOp from tests.

Please complete the following before merging:

• Update changelog.
• Make sure there are generated JSON files from the YAML test files.
• Test changes in at least one language driver.
• Test these changes against all server versions and topologies (including standalone, replica set, sharded clusters, and serverless).

[durran]

Test changes LGTM and am fine with the reasoning for skipping the currentOp test.

[alcaeus]

LGTM.

An alternative solution would be to choose a max server version (say, 6.99.0) and prohibit it from running on any future server versions.

That's what we usually did, but feel free to do this in a separate PR. IMO, there's no advantage to wait until the first driver breaks, so we may as well do this already.

[baileympearson]

The intent of this test seems to test that bypassed commands are passed (it tests with ping above) and then this test asserts that a command that isn't encrypted or bypassed errors.

Replacing currentOp with killOp (another command that is neither bypassed or encrypted) tests the same scenario.

[baileympearson]

@alcaeus I decided to address the currentOp test here but instead of adding a minimum server version, I changed the command to a killOp.