IGNITE-27068 .NET: LINQ: Support C# 14 span methods

[gurustron]

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[gurustron]

It is not possible to test this with .NET 8 SDK/runtime (C# 14 is needed). The added test does not actually do anything, testing was done in a separate branch with a separate project - gurustron@8d6d21a#diff-59756034c51e3f354b27eb11ce2a4611a1de92d3e29c726bebafc34114a31603

[Copilot]

Pull request overview

This PR updates the .NET LINQ query parser to handle C# 14 “first-class span” Contains calls by rewriting MemoryExtensions.Contains(ReadOnlySpan<T>, T) into Enumerable.Contains(IEnumerable<T>, T) so existing LINQ-to-SQL translation can produce IN (...) SQL.

Changes:

• Register a custom Remotion LINQ expression transformer to rewrite MemoryExtensions.Contains calls.
• Add a custom evaluatable-expression filter to prevent partial evaluation of ReadOnlySpan<T> implicit conversions.
• Add a LINQ SQL generation test related to Contains.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 5 comments.

File	Description
modules/platforms/dotnet/Apache.Ignite/Internal/Linq/IgniteQueryParser.cs	Adds an expression transformer + evaluatable-expression filter to support span-based Contains in LINQ parsing.
modules/platforms/dotnet/Apache.Ignite.Tests/Linq/LinqSqlGenerationTests.cs	Adds a SQL generation test for Contains producing an IN expression.

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[ptupitsyn]

Looks good to me in general, please see a few minor comments.