cli: Add 'sentry extract-origin-urls' command

Usage: swh sentry extract-origin-urls [OPTIONS]

  Extract origin URLs from events.

  This command allows to extract origin URLs from Sentry events related to a
  Software Heritage loader and dumps them to stdout.

Options:
  -u, --sentry-url TEXT           Sentry URL  [default:
                                  https://sentry.softwareheritage.org]
  -t, --sentry-token TEXT         Bearer token required to communicate with
                                  Sentry API (can also be provided in
                                  SENTRY_TOKEN environment variable)
                                  [required]
  -i, --sentry-issue-number TEXT  Sentry issue number to extract origin URLs
                                  from its events  [required]
  -e, --environment TEXT          Filter on environment: production or
                                  staging, both are selected by default
  -h, --help                      Show this message and exit.