feat(js/plugins/vertex): Model garden support for Claude 4.7

[ifielker]

Checklist (if applicable):

• PR title is following https://www.conventionalcommits.org/en/v1.0.0/
• Tested (manually, unit tested, etc.)
• Docs updated (updated docs or a docs bug required)

[gemini-code-assist]

Code Review

This pull request updates the Anthropic Vertex AI plugin to support Claude 3.7 Opus and introduces the 'thinking' (reasoning) feature and output configuration. Key changes include schema updates for thinking and output effort, logic to transform thinking blocks in requests and responses, and enhanced usage tracking for cache and ephemeral tokens. A review comment identifies a potential silent failure in the thinking configuration where a missing required parameter should trigger an error.