test(NODE-7280): remove test/mongodb.ts and its usage

[tadjik1]

Description

Summary of Changes

Remove test/mongodb.ts and all its' usage across the project (inside test/ folder).

Notes for Reviewers

This PR is pretty straightforward due to all the previous work for removing mongodb-legacy wrapper. And even though this file doesn't have any links to legacy driver usage we agreed to remove this file completely for consistency and readability reasons.

I had to make changes in examples/ folder, which is used by the docs team.

Please see my comments about action/dependency.test.ts updates: these tests are written differently, they run script in a separate nodejs process (using ts-node), and before they were expecting test/mongodb.ts passed as parameter. I changed this behaviour to dynamically import certain entities directly from src folder.

What is the motivation for this change?

Release Highlight

Release notes highlight

Double check the following

• Lint is passing (npm run check:lint)
• 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