Improve Cost Tracking & Observability

[cescoffier]

• Track and optimize token usage
• Condense tool result JSON
• Estimate invocation cost during planning
• Support tracing (OpenTelemetry), logging, and metric collection (Micrometer/OTEL bridge) - already quite advanced
• Document techniques to control/minimize token usage, like TokenWindowChatMemory instead of MessageWindowChatMemory,
  filter unnecessary MCP tools, select required tools dynamically via AiServices.toolSelector (to be implemented)

(From quarkusio/quarkus#50582)