fix: update dependencies and improve ECL assistant instructions

- Bump versions of several dependencies including @vscode/prompt-tsx, @eslint/js, @fluentui/react, and various @hpcc-js packages.
- Enhance the SYSTEM_MESSAGE for the ECL assistant to clarify its role and improve instruction clarity.
- Update the documentation citation format in the ECLDocsLookupTool to emphasize authoritative sources.

Signed-off-by: Gordon Smith <GordonJSmith@gmail.com>

Author: GordonSmith