schematelemetry,eventpb: add schema telemetry

[cockroach-teamcity]

Exalate commented:

Related PR: cockroachdb/cockroach#84761
Commit: cockroachdb/cockroach@262a70d

---

Release note (general change): CRDB will now collect schema info if
phoning home is enabled. This schema info is added to the telemetry log
by a built-in scheduled job which runs on a weekly basis by default.
This recurrence can be changed via the sql.schema.telemetry.recurrence
cluster setting. The schedule can also be paused via PAUSE SCHEDULE
followed by its ID, which can be retrieved by querying
SELECT * FROM [SHOW SCHEDULES] WHERE label = 'sql-schema-telemetry'.

Jira Issue: DOC-5276

[exalate-issue-sync]

Andrew Feierabend (andf-crl) commented:
No docs for telemetry changes.