revert: remove organization survey email functionality (#18642)

Remove all email sending parts to keep only the admin dashboard stats:
- Remove CLI command for sending survey emails
- Remove email templates for organization survey
- Remove send_organization_survey_email function
- Remove associated tests

This leaves only the organization utilization statistics in the admin dashboard.

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Co-authored-by: Claude <noreply@anthropic.com>

Author: ewdurbin