Extend the tool to use taxonomies and generic system types

# Description

### Current behavior
As of now, the toolkit works fine for the datamesh landscape dealing with data product system types, but it doesn't have a tool to list taxonomies and handle generic system types.

# Impact
The harness has trouble figuring out which taxonomy to use when creating a generic system type, and even when you ask it simple questions like “How many data products are deployed on the production mesh?”, it often gets stuck.

# Expected behaviour
They must be able to navigate easily among system types in different landscapes, both to answer general questions and to create system types within the correct taxonomy.

# Suggested fix
- Remove the hardcoded dataproduct word, replacing it with system-type
- Add a list_taxonomies tool in the MCP server