Add MCP support

[j08lue]

I think we should just provide MVP since it's a low lift and can be expected from a general-purpose interface like a STAC catalogue discovery interface.

Hypothetical user stories:

1. As developer of a chatbot application, I would like to interrogate data catalogues with natural language queries, so I do not need to understand catalogue- or domain-specific metadata concepts and API logic (STAC).
2. As a power user of ChatGPT or similar online chat applications, I want to use catalogue search right next to where I perform other tasks such as internet content discovery and generative AI.