[RFC] MCP support during a fuzzing campaign

[gustavo-grieco]

This is an experimental PR to add MCP commands in Echidna. These commands allow LLMs to query the state of fuzzing campaign, and perhaps make adjustments to guide or direct it.

Proposed commands to implement:

• Show number of corpus elements
• Show transactions in the corpus (using sequence number and pages of transactions)
• Search transactions in the corpus
• Insert element in the initial dictionary
• Change mutation weights
• Inspect coverage of a function
• Prioritize function

As expected, these commands can be used directly by LLM using a number of MCP clients:

Feel free to comment with more suggestions.

Note that this branch will not compile until we fork haskell-mcp-server (or use another similar library supported in stack/nix).