This change was finally made because the Delete function was the
only helper function that was not returning the ksql.ErrRecordNotFound
when no rows were found.
The other reason for this change is that we the most common use case is
by far for deleting a single element, and the philosophy of the library
is to optimize for the most common use-cases.
For making it easier to write queries for deleting many items
as well as many other less common use cases we
are already implementing the `kbuilder` package which is a
query builder.
This commit also fixes some bugs on this function and
adds a feature: Now you can return an kissorm.AbortIteration
error to abort the iteration and stop processing chunks.
This does not causes the call to QueryChunks to return an error,
since this is an expected error, thus, it is just ignored.