U4-8754 Single content queries like Get(int id) for content, media and members needs to execute a TOP 1 (or LIMIT 1)

updated a bunch of the remaining repositories to also use this pattern where applicable (repos using mappers aren't compatible without more work).

src/Umbraco.Core/Persistence/SqlSyntax/SqlSyntaxProviderBase.cs

@@ -503,6 +503,8 @@ namespace Umbraco.Core.Persistence.SqlSyntax
 
         protected abstract string FormatIdentity(ColumnDefinition column);
 
+        public abstract Sql SelectTop(Sql sql, int top);
+
         public virtual string DeleteDefaultConstraint
         {
             get