DRIVERS-3326: clarify retry behavior when errors with NoWritesPerformed are encountered

[baileympearson]

This PR clarifies the behavior when multiple errors with NoWritesPerformed are encountered (potentially possible when CSOT is enabled, or in the future with backpressure).

I wanted to add testing, but I ran into some difficulties that led me to believe it probably isn't worth adding test infrastructure just for this test.

• To test that the correct error is returned in this scenario, we need either a way to assert that the error returned is the first NoWritesPerformed error. However, command monitoring events do not include OP_MSG request ids and I don't know of another way to differentiate between requests.

To get around this, I wrote a simple JS proxy that added an incrementing counter to the payload of each response, so that the error a user receives has an identifier. This worked, but when I went to test this, I ran into another issue: to test this scenario, we need multiple retryable writes (CSOT or backpressure). Backpressure hasn't merged yet, so we can't rely on that feature. When I tried using CSOT, I could not actually reproduce this scenario because every CSOT error manifested as a timeoutMS error (which does not have a NoWritesPerformed error label).

One option is to make this PR depend on the client backpressure work and to put my proxy into drivers-evergreen-tools. This still might be more trouble than it's worth, because this is an additional CI variant for drivers, just for one test. The proxy must:

• run not on standalone servers (so retryable writes are enabled)
• proxy every node, or ensure we proxy the primary.
  • either of these options require extra work. either we must decode the URI to find all hosts, and then configure the proxy to proxy every host, and then provide a new URI against which the tests run OR we connect to the test URI, find the primary, proxy the primary and provide a new URI against which the tests can run.

Ultimately, I decided the testing here is more trouble than it's worth. Happy to reconsider if reviewers feel differently though.

Please complete the following before merging:

• Is the relevant DRIVERS ticket in the PR title?
• Update changelog.
• Test changes in at least one language driver.
• Test these changes against all server versions and topologies (including standalone, replica set, and sharded
  clusters).