Add organization_id to abuse_report_labels table

What does this MR do and why?

Add organization_id column and respective index + foreign key to abuse_report_labels.

All tasks of the issue

• Add organization_id column to abuse_report_labe... (#562569 - closed) (this MR)
• Populate organization_id in abuse_report_labels (#562570 - closed)
• Backfill organization_id column in abuse_report... (#562573 - closed)
• Add sharding_key to abuse_report_labels table d... (#562574 - closed)
• Set abuse_report_labels.organization_id as not ... (#562575 - closed)

MR acceptance checklist

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Related to #562569 (closed)