ensure reordered items match the bindings number

[pxpm]

WHY

BEFORE - What was wrong? What was happening before this PR?

Reported in #5634

We used ALL the entries to build the bindings, and when developer filtered the collection that would throw a "parameter number mismatch" error.

AFTER - What is happening after this PR?

We only add the number of bindings corresponding to the number of reordered items.

HOW

How did you achieve that, in technical terms?

Removed "extra", non reordered items from the keys we fetched from database.

Is it a breaking change?

I don't think so, no.