[CLI] Add command for `get_alerts_summaries`

[epalhares-tenchi]

Description

Expose a new CLI command that wraps the get_alerts_summaries method from the SDK.

Expected

• New command that calls get_alerts_summaries
• Accepts:
  • --organization-id (required)
  • --scan-target-ids (optional, list)
  • --search (optional)
  • --lang (optional)
• Uses existing SDK method
• Supports JSON output