Add option to select max position through ORDER BY + LIMIT 1

[ywarnier]

In the following code, obtaining the maximum value for a field uses a query in the select('MAX(n.'.$config['position'].')') form.

https://github.com/doctrine-extensions/DoctrineExtensions/blob/5d80d9d348e0384f0b0d2096bdd7c4a07009a866/src/Sortable/Mapping/Event/Adapter/ORM.php#L40C1-L41C51

In the case of a large table (hundreds of thousands of records) with an index that includes the field to be sorted, it can be about 10 times more efficient to issue a query of the form select(n.'.$config['position'].')') with an added sorting like ORDER BY n.'.$config['position'].' DESC LIMIT 1)').

Given the class is final, it is very complicated to include a change downstream to allow us to use this second method.

I would like to humbly request a feature that allows me to configure (maybe through the Gedmo annotations) this query to use the ORDER BY form rather than the MAX() form.

This already seems to be the case by default in ODM.php, but I'm not very familiar with the non-relational query builder.

DoctrineExtensions/src/Sortable/Mapping/Event/Adapter/ODM.php

Line 44 in 5d80d9d

$qb->sort($config['position'], 'desc');