Feature Request: Implement Message Search Functionality

[mwnu]

Description:
Currently, the Matrix MCP Server lacks tools for searching historical messages. Adding message search capabilities would:

1. Enable users to find specific content across rooms efficiently.
2. Support auditing, debugging, and data analysis workflows.
3. Align with Matrix clients’ native search features (e.g., Element).

Suggested Approach:

• Extend the existing Messages tool tier with a searchMessages endpoint.
• Support parameters: room_id, search_term.
• Integrate with Matrix’s search API or use a lightweight engine like Elasticsearch/Meilisearch.
• Ensure end-to-end encryption compatibility where applicable.

This feature would greatly enhance the MCP server utility for both small-scale and enterprise deployments.