fix: don't reverse commit order when cherry-picking

Fixes #726.  Looks like a980cc987d isn't sufficient.  It sorts the commits according to the ordering in history,  but then CherryPick ViewModel reverses the order.

This commit changes CherryPick ViewModel to use string.Join on the commit list without reordering,  so that the ordering is controlled entirely by the caller.

src/ViewModels/CherryPick.cs

@@ -85,13 +85,9 @@ namespace SourceGit.ViewModels
                 }
                 else
                 {
-                    var builder = new StringBuilder();
-                    for (int i = Targets.Count - 1; i >= 0; i--)
-                        builder.Append($"{Targets[i].SHA} ");
-
                     succ = new Commands.CherryPick(
                         _repo.FullPath,
-                        builder.ToString(),
+                        string.Join(' ', Targets.ConvertAll(c => c.SHA)),
                         !AutoCommit,
                         AppendSourceToMessage,
                         string.Empty).Exec();