Fix/2670 memoryextensions net10 followup

[LPEdwin]

This PR is a follow-up to #2670.

The previous patch on dev addressed part of the issue, but missed an additional case.

No new test was added, since LinqBsonExpression_Tests.Linq_Enumerables was already failing under .NET 10 and now passes with this fix.

The root cause: Contains can be invoked with 3 parameters. When the element type does not implement IEquatable<T>, a default comparer (null) is passed as the third parameter. This scenario was not handled by the previous patch.

Changes:

• Added .NET 10 target framework to the test project
• Added support for 3-parameter Contains

Refs #2670

[JKamsker]

Thank you for pointing that out! Somehow that must have slipped through.
Anyway, i took the chance to ensure dotnet 10 CI builds and tests correctly now.