feat: add supabase functions list

[jgoux]

Add supabase functions list

Summary

Adds the next CLI supabase functions list command.

The command builds a local Edge Functions inventory from the project config/filesystem and, when the project is linked and authenticated, enriches that inventory with remote deployment data from the Supabase Management API.

What Changed

• Registers supabase functions list under the next CLI functions command tree.
• Infers local Edge Functions with @supabase/config, including functions declared in supabase/config.toml.
• Fetches deployed functions from the linked project when credentials are available.
• Merges local and remote functions by slug so users can see both local presence and remote deployment status in one view.
• Adds text output with local status, remote status, version, updated timestamp, and entrypoint.
• Adds JSON output for agents and automation.
• Handles common partial-data cases gracefully:
  • unlinked project
  • linked project without credentials
  • remote API request failure
  • empty local/remote inventory
• Adds integration coverage for the command behavior.