#2953 Show the redaction diff and ask for confirmation before submitting an issue in log mode

Split out of swamp-club#2882.

swamp issue bug, feature, security and edit run an automatic redactor over the title and body before submitting. In log mode the reporter sees only a one-line summary (for example 'Redacted 1 hostnames'); the per-line changes are only visible in the --json output, after the issue is already public. When the redactor gets something wrong, the reporter learns they needed --no-redact only after the fact.

Request: in interactive log mode, print the redaction changes (before and after per line) and ask the reporter to confirm, submit unredacted, or abort before the issue is created. Non-interactive and --json runs keep today's behaviour.

The matcher false positives themselves (file names such as settings.local.json read as hostnames) are fixed under #2882.