Resolve "Snippets Usage Ping for Create SMAU"

What does this MR do?

Add usage data, on the granularity of event counts, for the following action:

• Snippet create/update
• Snippet comments

These counts are then collected as part of the existing usage data under the following keys:

• snippet_create
• snippet_update
• snippet_comment

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry for user-facing changes, or community contribution. Check the link for other scenarios.
• [-] Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides

Performance and testing

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

Related to #63888 (closed)