Before this commit, database with large amounts of `stock.move` records could face slow downs when trying to access Manufacturing Orders. While this is partially due to very heavy computations being done, another factor was the use of a loop in `_compute_forecast_information`. This loop would iterate over a recordset of `stock.move` records and put them into a dictionary, sorted by location. As the size of the recordset grew, this loop would take longer and longer. Here, we remove this loop and instead use a built in method to speed things up.

## Benchmarks:

|Record count|Time before|Queries before|Time after|Queries after| 
|------------|-----------|--------------|----------|-------------|
|6,262       |0.13s      |68            |0.12s     |68           |
|68,882      |0.60s      |112           |0.58s     |109          |
|432,317     |5.49s      |398           |3.68s     |309          |
|757,702     |15.33s     |1,141         |5.79s     |599          |

[opw-6310415](https://www.odoo.com/odoo/action-6450/6310415?debug=assets)

Forward-Port-Of: odoo/odoo#271677