…store filename along with page data:
- set filename on crawler load, if not already set, otherwise use
existing
- store filename per crawler instance in <crawlid>:nextWacz
- add 'filename' field to page when writing pages to redis
- clear wacz filename when wacz is uploaded to set a new one
- fixes#747
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Co-authored-by: Tessa Walsh <tessa@bitarchivist.net>