Add instrumentation for notes on work items

What does this MR do and why?

Resolves https://gitlab.com/gitlab-org/gitlab/-/issues/571901+ by adding new internal event instrumentation for creation/updates/deletes of notes on work items.

Achieves so by adding the net new events and relevant metrics, as well as adding calls to a new InstrumentationService in the correct services which ensures the correct work item metadata is included in the payload according to the schema.

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Related to #571901