Performance Issues, Out of memory with large number of users

This is just the plain patch of the MR.
Just to note this is quite a refactor as I created another service to handle the optional batch processing and added in a drush command so you can run the command with a separate cron.

Have tested this on a site that has 40,000 users that we class as inactive and via drush seemed to run fine.

To note I did not add batching to the delete command as this was not something I wanted, but someone else might want to update it to do that.

I also added an option to enable/disable cron so you can run everything when you want, will also need to run update to make sure that cron gets enabled.

Oh forgot to mention the drush commands:

• drush block-inactive-users:block --run

Without --run no updates will be made just for testing/count.

This is a massive effort. Thanks for your contribution @3li. I will need to review this and probably release it as part of 3.0 beta. Especially, that we'll be dropping support for < php 7.4.

Thanks @3li, I did a manual test on a large set of users and confirming that it works as expected so RTBC+1

Hey 3li,

Decide to move this to 3.x and create a beta build with the changes. I am happy to take over the PR and sort out the conflicts. Let me know if that's okay.

Hey rawdreeg,
Yeh thats fine, let me know if I can do anything though.