Add event name information for external status check changes

What does this MR do and why?

This MR resolves the following issues:

• 369333
• 369334

... which are described in this epic and it's parent epic

When editing the external status check attributes in project settings now the event_type attribute of the audit event contains a meaningful value and not the default value of audit_operation. The value used now:

• external_status_check_name_updated for the name change
• external_status_check_url_updated for the URL change

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.