Use OmegaEdit Data Editor as an extension dependency

## Goal

Make the Apache Daffodil VS Code extension use the standalone OmegaEdit Data Editor VS Code extension instead of carrying and starting an embedded Data Editor implementation.

## Plan

- Declare the OmegaEdit Data Editor extension as a VS Code extension dependency.
- Keep Daffodil's existing `extension.data.edit` command, but delegate file opening to the OmegaEdit extension API.
- Convert Daffodil debugger `daffodil.data` events into external current-byte highlights in OmegaEdit.
- Remove the embedded Svelte Data Editor, OmegaEdit server/client lifecycle code, and related launch configuration settings.
- Update tests so Daffodil validates the integration contract with a small fixture extension instead of starting the old embedded editor stack.
- Update documentation to describe the external Data Editor dependency and Daffodil's responsibility for open/highlight integration.

## Validation Criteria

- TypeScript build, lint, VS Code integration tests, and license checks pass.
- Opening a Daffodil data file still works through the existing command.
- Debugger data-position events highlight and reveal the current byte in the OmegaEdit Data Editor.

Start with the existing extension.data.edit command, debugger daffodil.data event handling, and VS Code integration tests. Trace the current embedded editor and lifecycle configuration, then examine the small fixture extension used for the integration contract. Done means the TypeScript build, lint, integration tests, and license checks pass, with file opening and current-byte highlighting working through OmegaEdit.

Written by the indexing model from the issue text.