chore: deduplicate GenerateSomeExpression and relocate misplaced test fixture

GenerateSomeExpression now delegates to WrapInOptionalSome instead of
duplicating the Optional<T>.Some() SyntaxFactory pattern. Moved
property_getter_fstring_format fixture into TestFixtures/properties/
for consistency with other property tests.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: antonsynd

…/property_getter_fstring_format.expected …/property_getter_fstring_format.expectedsrc/Sharpy.Compiler.Tests/Integration/TestFixtures/property_getter_fstring_format.expected renamed to src/Sharpy.Compiler.Tests/Integration/TestFixtures/properties/property_getter_fstring_format.expected src/Sharpy.Compiler.Tests/Integration/TestFixtures/property_getter_fstring_format.expected renamed to src/Sharpy.Compiler.Tests/Integration/TestFixtures/properties/property_getter_fstring_format.expected

@@ -1122,18 +1122,7 @@ private ExpressionSyntax WrapInOptionalSome(ExpressionSyntax value, OptionalType
     /// Generates: Optional<T>.Some(value)
     /// </summary>
     private ExpressionSyntax GenerateSomeExpression(FunctionCall call, OptionalType opt)
-    {
-        var underlyingType = _typeMapper.MapSemanticType(opt.UnderlyingType);
-        var arg = GenerateExpression(call.Arguments[0]);
-
-        return InvocationExpression(
-            MemberAccessExpression(
-                SyntaxKind.SimpleMemberAccessExpression,
-                GenericName("Optional")
-                    .WithTypeArgumentList(TypeArgumentList(SingletonSeparatedList(underlyingType))),
-                IdentifierName("Some")))
-            .WithArgumentList(ArgumentList(SingletonSeparatedList(Argument(arg))));
-    }
+        => WrapInOptionalSome(GenerateExpression(call.Arguments[0]), opt);
 
     /// <summary>
     /// Generates: Result&lt;T, E&gt;.Ok(value)