feat: add BroadcastListRecipientsAsync method

[dielduarte]

Adds BroadcastListRecipientsAsync for GET /broadcasts/{id}/recipients, plus a matching CLI command.

Spec: resend/resend-openapi#97
Node reference: resend/resend-node#1078

Tests: 192/192. Build clean.

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Summary by cubic

Adds an API and CLI to list a broadcast’s recipients by event type. Previously clients couldn’t fetch recipients; now they can paginate and filter by email or bounce type with event-specific details, without breaking existing behavior.

• Adds BroadcastListRecipientsAsync(Guid broadcastId, BroadcastRecipientEventType type, BroadcastListRecipientsQuery? query) returning PaginatedResult; introduces enums/models for event types, bounce types, clicked links, and per-recipient counts for opened/clicked.
• Validates bounce-type usage: the client rejects BounceType unless type is Bounced; the CLI enforces the same.
• Adds CLI subcommand: resend broadcast recipients with --email, --bounce-type, --limit, --before, --after, --json; JSON output is a proper array and table cells are escaped.
• Extends the fake API server for GET /broadcasts/{id}/recipients (NotFound for Guid.Empty) and covers the endpoint with tests.

^{Written for commit 234cc5d. Summary will update on new commits.}

[cubic-dev-ai]

All reported issues were addressed across 11 files

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[cubic-dev-ai]

0 issues found across 3 files (changes from recent commits).

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

<sub>Requires human review: Auto-approval blocked by 2 unresolved issues from previous reviews.

Re-trigger cubic</sub>