Fixed: Change license_seat changing method to properly 'true up' license seats

[uberbrady]

A customer reported that the number of license seats that they had defined for the license didn't match up with the number of license seats reported when they clicked the 'seats' tab.

Somehow, they managed to have only 5 empty license_seat records, even though they had defined 6 as the number of seats that are in the license.

I realized that, no matter how I adjust the seat count in the license, the issue will never get rectified - when I changed the seat count to 7, it correctly added a new blank seat - but there were still only 6 of them. So nothing I was going to be able to do was going to fix their data barring manually editing their database.

I've modified our callback hooks to instead take the 'true' seat count (from literally counting the number of records in the license_seats table) instead of the 'previous' seat count. This means that if any other user has a license_seat count vs. $license->seats mismatch, they can just do an edit to the seat count, and it should correct the issue and 'true up' the database to match.

[what-the-diff]

• The oldSeatCount was being set to 0 if the original seats value wasn't found.
• This meant that you could never get your license_seats back into whack with a License record, because it would always be trying to delete from zero instead of using an accurate count of existing records.
• Now we use $license->license_seats_count which is more accurate and will allow us to 'true up' our counts when they are out of sync (which can happen). It also means that this code should work better in general for all cases where there might not have been any previous seat values saved on the model yet or whatever else may cause issues with getting at those original attributes via $license->getOriginal()['seats'].

[snipe]

Looks great, thank you!