Fix S3431 FN: Multiline statement should not be count as one line statement

[sebastien-marichal]

S3431 has an exception for single-line tests.
To check this, we count the number of statements in the method body

sonar-dotnet/analyzers/src/SonarAnalyzer.CSharp/Rules/ExpectedExceptionAttributeShouldNotBeUsed.cs

Lines 28 to 33 in b26c926

	protected override bool HasMultiLineBody(SyntaxNode syntax)
	{
	var declaration = (MethodDeclarationSyntax)syntax;
	return declaration.ExpressionBody is null
	&& declaration.Body?.Statements.Count > 1;
	}

However, this will be count has one:

[TestMethod]
[ExpectedException(typeof(InvalidOperationException))]
public void TestMethod()
{
    try // This is one statement
    {
        Console.ForegroundColor = ConsoleColor.Black;
        using var _ = new ConsoleAlert();
        Assert.AreEqual(ConsoleColor.Red, Console.ForegroundColor);
        throw new InvalidOperationException();
    }
    finally
    {
        Assert.AreEqual(ConsoleColor.Black, Console.ForegroundColor);
    }
}

public sealed class ConsoleAlert : IDisposable
{
    private readonly ConsoleColor previous;

    public  ConsoleAlert()
    {
        previous = Console.ForegroundColor;
        Console.ForegroundColor = ConsoleColor.Red;
    }
    
    public void Dispose() =>
        Console.ForegroundColor = previous;
}

The method body has only one statement which is the try statement, discarding the lines within the try statement.
This applies to some other statements as well (non-exhaustive):

• Block
• CatchClause
• CheckedStatement
• DoStatement
• FinallyClause
• FixedStatement
• ForEachStatement
• ForEachVariableStatement
• ForStatement
• IfStatement
• LockStatement
• SwitchStatement
• TryStatement
• UncheckedStatement
• UnsafeStatement
• UsingStatement
• WhileStatement

This does not seem to be an issue in VB.NET, might need more investigation.