fix(NODE-6552): remove cache and use toStringTag in type helpers

[nbbeeken]

This partially reverts commit 61537f5.

Description

What is changing?

• revert "Improve serialization performance"

Is there new documentation needed for these changes?

No

What is the motivation for this change?

• This commit appears to be the source of failure observed in the driver performance test: "ldjsonMultiFileUpload"

Release Highlight

Fix issue with the internal unbounded type cache

As an optimization, a previous performance improvement stored the type information of seen objects to avoid recalculating type information. This caused an issue in the driver under extreme load and high memory usage as the cache grew. The assumption was that garbage collection would clear it enough to sustain normal operation. The cache is now removed and other optimal type checking is used in its place.

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