refactor(agents)!: move goap and llm-based planners to a new module

[antoniibelyshev]

Created agents:agents:planners module, moved GOAPPlanner and SimpleLLMPlanner to the new module. Also made adjustments to the planners structure:

• moved initializeState and provideOutput from AIAgentPlannerStrategy to AIAgentPlanner
• removed AIAgentPlannerStrategyBuilder in favor of `AIAgentPlannerStrategy.create(name, planner) since none other configurable parameters are available.
• removed PlannerAIAgent.builder() in favor of configuring planner agents using AIAgent.builder().plannerStrategy(...)...

BREAKING:

• Usage of GOAP planner and LLM-based planner now requires an additional dependency: agents:agents-planner
• AIAgentPlanner and JavaAIAgentPlanner abstract classes now have two additional abstract methods: initializeState and provideOutput.
• AIAgentPlannerStrategy now does not accept initializeState and provideOutput as parameters to the constructor: AIAgentPlannerStrategy(name, planner), plus a convenience method AIAgentPlannerStrategy.create(name, planner) for java. AIAgentPlannerStrategy.builder() and AIAgentPlannerStrategy.goap() are now removed.

[Amaneusz]

This is a solid piece of work 💪

I see two things that block the merge as of this moment:

• Failing build :agents:agents-features:agents-features-acp:checkSplitPackages - I haven't looked into it yet tbh
• Referencing non existing JavaTypedAIAgentPlanner type in examples

Besides that:

• I added few minor comments, none of them is blocking
• I would edit BREAKING section in PR description:
  • Existing imports of ai.koog.agents.planner.goap.* and ai.koog.agents.planner.llm.* now
    require a new agents-planner module dependency
  • number of generics needed by AIAgentPlanner (and Java...) increased from 2 to 4 - migth be worth mentioning here if someone had their custom strategy
  • AIAgentPlannerStrategy constructor changed - it's a public class, worth noting
  • removal of AIAgentPlannerStrategy methods: builder(name) and goap(...), also top level AIAgentPlannerStrategy(...) factory function and PlannerAIAgent.builder()

[Amaneusz]

LGTM!

As discussed on call:

• no-arg constructors for AIAgentPlanner and JavAIAgentPlanner silenty disable users from serialization-based features (ie persistence) - a KDoc might be valuable, otherwise we accept the risk that we think is negligible
• examples for sping-ai will become stale as they reference an old version of AIAgentPlanner that accepts 2 generics instead of 4 - we are fine with this as examples refer strictly to 0.8 version and might be upgraded later on if necessary