[DO NOT MERGE] Fix COUNT(expr) with nested ternary expressions miscounting documents (#64)

[McNultyyy]

Summary

Fixes #64 — COUNT(expr > 0 ? 1 : undefined) incorrectly counts documents where the expression evaluates to undefined when nested ternary expressions are involved.

Root Cause

ExprToString in CosmosSqlParser did not parenthesise TernaryExpression or CoalesceExpression nodes when they appeared as operands of higher-precedence operators (binary, unary, BETWEEN, IN, LIKE).

When the SDK transforms a query like:

SELECT VALUE COUNT((IS_DEFINED(c.creditValue) ? c.creditValue.amount : c.grossValue.amount) > 0 ? 1 : undefined) FROM c

The handler round-trips it through SimplifySdkQuery → ExprToString → re-parse. Without parentheses, the re-parsed AST has completely different semantics:

• Before fix: IS_DEFINED(c.creditValue) ? c.creditValue.amount : (c.grossValue.amount > 0 ? 1 : undefined)
• After fix: (IS_DEFINED(c.creditValue) ? c.creditValue.amount : c.grossValue.amount) > 0 ? 1 : undefined

Fix

Added WrapIfLowPrecedence helper method that wraps ternary and coalesce sub-expressions in parentheses when they appear inside operators with higher precedence, ensuring the serialized SQL re-parses to the same AST.

Test Coverage

Added 10 integration tests covering:

• Simple ternary in SELECT VALUE (condition true/false)
• Nested ternary in SELECT VALUE (inner resolves, comparison succeeds/fails)
• Simple ternary in COUNT (condition false → not counted)
• Mixed documents with COUNT (only matching docs counted)
• Nested ternary in COUNT — the exact bug scenario (inner resolves to 0, comparison fails → not counted)
• Nested ternary in COUNT (inner resolves to positive → counted)
• Fallback path when IS_DEFINED is false
• Multi-aggregate query mirroring the original issue's pattern

Version

Bumped to 4.0.18.