[MIG] Migration of account_renumber to 8.0.

@guewen, yeah, I use to talk about better or worse instead of bad and wrong, and obviously your way is better, because it can have the same performance or better, never worse. I always appreciate your tips, so thank you!

@jordillinares Please accept these comments as part of the reviewing process, and think that in most cases, this is only for saying: this is not ready yet to be merged, not that the PR is rejected. Sometimes, a module is clearly seen as not valid, and it's rejected, but that doesn't depend only in one person opinion.