feat: [390] - Purge non-confirmed users periodically

[lucifercr07]

Changes:

• Related issue: [FEATURE] Purge non-confirmed users periodically #390
• Added new method in ScheduleService to purge non-confirmed users that haven't confirmed their email-address for 14 days
• Added new method to scheduleLong()
• 14 days as configurable in application.properties under app.schedule.delay.user.cleanup
• Added unit test

[lucifercr07]

Currently this is just finding the users which have not confirmed and deleting all whose creation date is before 14 days.
@Nonononoki can you please confirm below points once:

1. If we need to archive/soft-delete them rather than purge? Can see something as user-hide table shall we utilise it and purge after 90 days?
2. Does any of the details need to be stored or all the details of user need to be purged?
3. Also is there a mechanism already in place to notify these users before 14 days to confirm their email address else account would be deleted?

[lucifercr07]

Will add unit-tests once above approach is confirmed.

[Nonononoki]

1. Purge, no soft delete
2. No, delete all data
3. I don't think any email notification is needed.

[lucifercr07]

@Nonononoki please review once have added unit tests.

[Nonononoki]

@lucifercr07 You can use the date filtering directly in the JPA (e.g. `findByConfirmedIsFalseAndDatesCreationDateBefore(Date date))

[lucifercr07]

@Nonononoki thanks have addressed the issue.

[Nonononoki]

Code is looking good, but why did you need to change the RegisterServiceTest?

[lucifercr07]

Wanted to create new mock users as only testUsers was getting used across all tests in that file. Also delete users method would throw error since few of the users would be purged and couldn't be found. Please let me know if you feel there's any other effective way to do this would change accordingly.

[lucifercr07]

@Nonononoki please let me know if any changes required to be done here.

[Dremor]

Could be a good idea to double check before purging user... you know, to avoid risking purging the whole database in the case of "userRepo.findByConfirmedIsFalseAndDatesCreationDateBefore" not being restrictive enough. Btw, were is this query implemented? I can't find it on the PR diff.