Leverage the LSP / Intellisense of a connected IDE (VS Code / Visual Studio)

### Describe the feature or problem you'd like to solve

Setting up local LSP server for Copilot CLI is unnecessary when a connected IDE can serve those operations

### Proposed solution

Manually setting up an LSP server for Copilot CLI to use is non-trivial.

Suggestion: When Copilot CLI is connected to an IDE like VS Code or Visual Studio, LSP tools like go-to-definition, find-references, hover-info, etc could be forwarded to the IDE - leveraging the LSP and Intellisense functionality there.

### Example prompts or workflows

- User opens Copilot CLI on a repository
- User open VS code on the same repository
- See: Agent operations on the repository leverage semantic understanding (via LSP/Intellisense) served by the IDE, rather than grep operations.

### Additional context

_No response_

Start by examining how Copilot CLI connects to a repository and how it could communicate with a connected VS Code or Visual Studio instance. Define the forwarding path for go-to-definition, find-references, and hover-info, then verify that example CLI workflows use the IDE's LSP or Intellisense results instead of grep-based operations.

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