Perf: Refactor ProductDrive#index with service

[coalest]

Doesn't resolve any ticket.

Description

The product drives index page was mentioned to be slow in production.

Turns out it we were running two aggregate queries for every product drive (for the item quantity and number of unique items).
So listing 10 product drives meant 20 queries just to calculate the totals.
Also this page isn't paginated, so that makes the issue worse. (Although it looks like it used to be?)

Type of change

• Performance change (should be identical behavior for users)

How Has This Been Tested?

Passes test suite and tested locally.

Screenshots

The performance beforehand scales linearly with number of product drives, so the more i add the worse it got.

These screenshots are when ~10 product drives were being returned.
Before:

After:

[cielf]

I took a look at how product drives are distributed across organizations in prod -- it's very uneven, but about half a dozen organizations have more than 100, and one over 500 -- pagination isn't something they've asked for, but it may make sense. I'll throw it into the "inbox" for consideration.