Audit events for product analytics
<!-- Audit Event documentation: See https://docs.gitlab.com/ee/administration/audit_events.html -->
<!-- Streaming Audit Event documentation: See https://docs.gitlab.com/ee/administration/audit_event_streaming.html -->
## Audit need
<!-- Describe the real-world use case for the audit event you want to introduce, and explain the closest thing that GitLab already captures. -->
Changing Product Analytics settings and controls is sensitive. Examination of where data is being sent and accessed from will come up in audits.
## Proposal
<!-- Describe the audit event you are proposing should be added, including any details of what should be captured, how, and why. -->
Add audit events whenever the following changes occur with respect to product analytics:
* A new cluster is specified in GitLab for Product Analytics
* An existing cluster is removed from GitLab for Product Analytics
* The project dashboard configuration file source has changed
* A new dashboard is created
* A dashboard is deleted
* A dashboard is modified
* An image link is created (can be sent to external source)
### Streaming-only event or normal event?
<!-- Should this event be a streaming-only audit event or also logged to GitLab's database? Consider the
volume of data that will be generated by the event when answering this. -->
Add this event for both streaming and normal audit event reporting.
epic