Clarify what happens to the user's data when the user is deleted

Summary

When a user is deleted and there is no other user in a different directory, his details are not deleted immediately.

Instead, they are preserved for 7 days.

This includes:

• SSH keys
• GPG Keys
• Access tokes
• all user related data stored by apps

This applies to:

• users from an external directory (e.g. JIRA or LDAP)
• internal users (from the internal directory)

Steps to Reproduce

1. Step 1
2. Step 2

Expected Results

The documentation should cover the current implementation.

Actual Results

The Users and groups - Deleting users and groups page provides the following (incorrect) explanation:

If the user or group does not exist in another directory, Bitbucket Server assumes the intent was to permanently delete them, and we delete the users permissions, SSH keys and 'rememberme' tokens.