QA selectors for the audit events app are now customisable

What does this MR do?

Currently, the qaSelector being passed in ee/app/views/admin/audit_logs/index.html.haml:6 doesn't actually get used and is overridden by the hardcoded value in AuditEventsTable and AuditEventsFilter.

This MR makes it so these are customisable and means you can define tableQaSelector and filterQaSelector for each instance of the app.

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines
• Style guides
• Separation of EE specific content

Availability and Testing

1. Confirm the table has the QA selector admin_audit_log_table
2. Change the QA selector in ee/app/views/admin/audit_logs/index.html.haml and confirm it is reflected in the table
3. Empty string and/or remove the QA selector and confirm it is reflected in the table
4. Confirm the filter has the QA selector admin_audit_log_filter
5. Change the QA selector in ee/app/views/admin/audit_logs/index.html.haml and confirm it is reflected in the filter
6. Empty string and/or remove the QA selector and confirm it is reflected in the filter

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.