make provided JB tools more usable from other plugins

As dev of Qodo Gen plugin, would be nice to have easier usage of provided JB tools by:

1. split MCP server from http server (i.e. I need only tools to be used directly from IDE and not through http server)
2. remove hardcoded checks for Claude/Node exitance in `MCPServerStartupValidator`
3. make next `private` funs public (so far I just copy-paste them): `MCPService#parseArgs` `MCPService#toolHandle` `MCPService#schemaFromDataClass`, also latter need correctly process array (type info probably needed)

Also we use Anthropic MCP SDK https://github.com/modelcontextprotocol/kotlin-sdk would be nice if JB mcp-server be internally type compatible with it (have to write proxies by myself for now)

But overall it works great! Many Thanks for your work!