feat(mcp): relax MCP Schema JSON deserialization constraints (#37)

* feat(mcp):  relax MCP Schema JSON deserialization constraints

- Add @JsonIgnoreProperties(ignoreUnknown = true) annotation to all record
classes in McpSchema to make JSON deserialization more robust by ignoring
unknown properties.
- Make the JsonSchema record public

Resolves #36

This improves compatibility with third-party implementations like Cursor that are not MCP Schema compliant.

Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>