[Task]: Backend support for seed files

[tw4l]

Description

Core requirements:

• Add endpoints to upload and delete a seed list file (file stored in s3, make sure to check storage quota first, validate that file has expected .txt extensiom is <= 25 MB, scope type is set to "page" if seed list is uploaded, and seeds array is null/empty), save file db record in new mongodb collection
• Add support for seed file (referenced by id) to /crawlconfigs/ POST + PATCH endpoints, ensure dereferenced files are deleted
• Add background cron job to check for and clean up orphaned seed files (and maybe collection thumbnails as well?)
• Pass seed file to crawler if provided

Related tasks:

• Pass lastCrawlStats to GET /crawlconfigs list and detail endpoints
• Return seed file total size in org storage stats

Context

No response