Add BSON type testing

[danielfrankcom]

This change adds tests for general-purpose BSON type behavior. This differs from operator-specific behavior that exists elsewhere and overlaps with some of the behavior of these types.

As part of this change I moved the existing core/bson_types/test_bson_types_ordering.py file into the correct directory, and split it up to better group the tests logically.

[documentdb-triage-tool]

🤖 Auto-triaged by documentdb-triage-tool.

Applied: compatibility test, enhancement
Project fields suggested: Component test-coverage · Priority P2 · Effort XL · Status Needs Review
Confidence: 0.85 (mixed)

Reasoning

component from path globs (test-coverage); effort from diff stats (2102+540 LOC, 27 files); LLM: Adds new BSON type test coverage and reorganizes existing tests into a better logical structure, touching compatibility test files.

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