Add Dependabot alerts REST API functions [Changelog 2022-10-18]

[MariusStorhaug]

Summary

Dependabot alerts have no coverage in this module — there is no Dependabot command category under src/functions/public/. The Dependabot alerts REST API lets you list and update vulnerability alerts at the repository, organization, and enterprise level — essential for supply-chain security automation and reporting.

Changelog reference

• 2022-09-22 — Dependabot alerts REST API is now available in public beta
• 2022-10-18 — Dependabot alerts organizational-level REST API: retrieve all Dependabot alerts at the organization level via REST, supplementing the repo-level alerts API and the alerts webhook.

Desired capability

Add functions for the Dependabot alerts REST API:

• Get-GitHubDependabotAlert — list/get alerts at repo, org, and enterprise level, with filters (state, severity, ecosystem, package, scope).
• Set-GitHubDependabotAlert — update alert state (dismissed/open) with dismissed reason/comment.

Acceptance criteria

• Functions use Invoke-GitHubAPI and the active GitHubContext; pagination handled.
• Repo-, org-, and enterprise-level listing supported via parameter sets.
• Typed alert objects with default formats (severity, package, advisory summary).
• Integration tests against an owned repo with Dependabot alerts enabled (skipped gracefully when unavailable).

Notes

• Requires security_events (or repo) scope; org/enterprise listing requires appropriate admin permissions.