Add gitweb lister

we need a lister for gitweb instances

Tor's one is a sample instance that we want to archive and that we can use for testing, but there are many others out there

• swh/devel/swh-lister!485 (merged): Implementation
• docker: various forges ingestion until it works on "all" cases
• swh/infra/sysadm-environment#4984 (closed): Deploy to staging
• swh/infra/sysadm-environment#4986 (closed): Deploy to production
• swh/devel/swh-web!1159 (merged): Reference in archive coverage widget
• Add type to add-forge-now and coverage widget ui

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Migrated from T1800 (view on Phabricator)