feat(NODE-3793): Remove offensive language from code and tests

[ljhaywar]

Description

NODE-3793

What is changing?

Remove and deprecate (when removal is not possible) all references to "slaveOk" in the source code and tests. Note that spec test updates are being tracked in NODE-3791

Is there new documentation needed for these changes?

No

What is the motivation for this change?

Following the guidance documented in tools.ietf.org/id/draft-knodel-terminology-00.html, we will remove all oppressive and unnecessarily gendered language in driver documentation, code, tests, specs, and spec tests.

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>
• Changes are covered by tests. I'm unsure and have commented below
• New TODOs have a related JIRA ticket

[ljhaywar]

General question: Are these changes covered by tests? I tried changing the return value of slaveOk() in db.ts to both true and false (instead of this.secondaryOk;) and all of the tests passed. I did the same for slaveOk() in read_preferences and the tests continued passing. It seems odd that these changes wouldn't be covered at least indirectly by tests.

[dariakp]

Just capturing this particular thought for now, not a full review

[ljhaywar]

Going to add a few more tests. Will comment here when I'm done

[ljhaywar]

I've finished adding tests. This is ready for review.

[dariakp]

Looks good to me :)