Deduplicate SQL query parameters across expression processors

[snaumenko-st]

When the same closure variable or row-filter collection is referenced multiple times in a single query (e.g. two .Where() clauses, both sides of a Union, or a Where + Select), the ORM previously emitted one DB parameter per reference. After this change each unique value is bound exactly once per compiled query.

Summary

• Scalar/TypeId bindings: widens the bindingsWithIdentity dedup table from per-ExpressionProcessor to per-SqlCompiler, so all processors in one compilation share it. TypeId bindings are cached by TypeId in a new typeIdBindings dictionary on SqlCompiler.
• Row-filter scalar bindings (ComplexCondition / Auto+TempTable path): adds a ScalarFilterKey(TypeMapping[], List<Tuple>) dictionary in CommandFactory.CreateQueryPart that caches the full filterValues[][] result per unique filter list, mirroring the existing TVP dedup pattern.
• TVP bindings: adds a TvpParameterKey(TypeMapping, List<Tuple>) dictionary in CommandFactory.CreateQueryPart so two row filters referencing the same collection share a single TVP parameter.

Test plan

• ClosureParameterReferencedMultipleTimesInQueryIsBoundOnce — same int closure in two Where clauses shares one parameter
• TypeIdReferencedInBothUnionBranchesIsBoundOnce — TypeId parameter shared across Union branches
• SmallRowFilterArrayReferencedInFilterAndProjectionIsBoundOncePerValue — small Contains list deduped across Where + Select
• SmallRowFilterArrayReferencedInBothUnionBranchesIsBoundOncePerValue — same array in both Union branches
• LargeRowFilterCollectionReferencedMultipleTimesUsesDistinctParameterValues — large list (TVP) referenced twice shares one TVP parameter
• ExplicitTvpAlgorithmReferencedMultipleTimesUsesDistinctParameterValues — explicit TVP algorithm shares one parameter
• BooleanClosureReferencedMultipleTimesIsNotBoundAsDbParameter — boolean closures expand to SQL constants, not DB params
• DecimalClosureReferencedInFilterAndProjectionIsBoundOnce — decimal closure in two Where clauses shares one parameter
• TakeClosureReferencedInFilterAndPagingUsesDistinctParameterValues — same int used in Where (Regular) and Take (LimitOffset) stays distinct
• DistinctClosureValuesRemainSeparateParameters — guard: different values produce separate parameters

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