fix(NODE-5750): RTTPinger always sends legacy hello

[nbbeeken]

Description

What is changing?

• Adds serverApi and helloOk logic to RTTPinger
• Calls destory on connection when an error is recv-ed
• Replaced symbol properties with string properties

Is there new documentation needed for these changes?

No

What is the motivation for this change?

Fixes a connection leak when serverApi is enabled.

Release Highlight

Fix connection leak when serverApi is enabled

When enabling serverApi the driver's RTT mesurment logic (used to determine the closest node) still sent the legacy hello command "isMaster" causing the server to return an error. Unfortunately, the error handling logic did not correctly destroy the socket which would cause a leak.

Both sending the correct hello command and the error handling connection clean up logic are fixed in this change.

Double check the following

• Ran npm run check:lint script
• Self-review completed using the steps outlined here
• PR title follows the correct format: type(NODE-xxxx)[!]: description
  • Example: feat(NODE-1234)!: rewriting everything in coffeescript
• Changes are covered by tests
• New TODOs have a related JIRA ticket