Port Bitbucket lister to the new Lister API

Characteristics of the lister:

• instances: unique
• API URL: "https://api.bitbucket.org/2.0"
• query: "/repositories?after=%s"
• state:
  • indexable DateTime
• auth: Oauth https://developer.atlassian.com/bitbucket/api/2/reference/meta/authentication
• rate limiting: 1000 https://support.atlassian.com/bitbucket-cloud/docs/api-request-limits/
• pagination: 10-100
• page format: JSON

Related to swh-scheduler#2442 (closed)

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Migrated from T2955 (view on Phabricator)