Tool Group - Initializing Just in time

[john-mcpeek]

We pass through user Authorization headers to MCP servers. We need to delay initializing MCP clients until the first user request. This way the users OAuth token will be used for the initialization calls. We use Spring AI's spring.ai mcp.client.initialized=false to enable this. However, when a tool group is configured, the initialization happens at startup regardless.

We need an equivalent to to Spring AI's spring.ai mcp.client.initialized=false, but for Tool Groups. This would enable just in time configuration of Tool Groups and MCP clients.