CSHARP-5777: Avoid ThreadPool-dependent IO methods in sync API

[sanych-sun]

Consolidate Stream extension methods + improve code coverage.
Includes fix for Tailable_cursor_should_be_able_to_be_cancelled_from_a_different_thread_with_expected_result flaky test.

[Copilot]

Pull Request Overview

This PR refactors stream extension methods to consolidate implementations and avoid ThreadPool-dependent I/O methods in the synchronous API. The main changes involve replacing the old API that used OperationContext and TimeSpan parameters with a cleaner API that uses int timeoutMs and CancellationToken parameters directly.

Key Changes:

• Consolidated stream extension methods with separate timeout handling for sync and async operations
• Replaced TimeSpan timeout parameters with int timeoutMs (milliseconds) for consistency
• Improved test coverage by adding dedicated tests for byte array overloads of WriteBytes methods

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/MongoDB.Driver/Core/Misc/StreamExtensionMethods.cs	Complete refactoring of ReadBytes/WriteBytes extension methods with new timeout handling mechanism; sync methods now use Timer-based approach while async methods use Task.WhenAny pattern
tests/MongoDB.Driver.Tests/Core/Misc/StreamExtensionMethodsTests.cs	Updated all tests to use new API signatures; added comprehensive test coverage for byte array WriteBytes methods; renamed tests for better clarity
src/MongoDB.Driver/GridFS/GridFSBucket.cs	Updated ReadBytes/ReadBytesAsync calls to use new API with named cancellationToken parameter
src/MongoDB.Driver/Core/Connections/BinaryConnection.cs	Updated ReadBytes/WriteBytes calls with TimeSpan-to-milliseconds conversion at call sites
src/MongoDB.Driver/Core/Connections/Socks5Helper.cs	Updated ReadBytes/ReadBytesAsync calls to use new API with named cancellationToken parameter
src/MongoDB.Driver/Core/Compression/SnappyCompressor.cs	Simplified ReadBytes calls by removing unnecessary timeout parameters for in-memory operations

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[Copilot]

The test method is named WriteBytes_with_byte_buffer_should_throw_when_buffer_is_null but it's testing the byte array overload instead of the IByteBuffer overload. The variable should be declared as IByteBuffer buffer = null; to properly test the intended method.

Suggested change

	byte[] buffer = null;
	IByteBuffer buffer = null;

[Copilot]

Generic catch clause.

Suggested change

	catch (Exception)
	{
	// suppress any exception
	}
	catch (ObjectDisposedException)
	{
	// suppress ObjectDisposedException
	}
	catch (IOException)
	{
	// suppress IOException
	}