FunctionFlow behavior in plan object.

[lemillermicrosoft]

dd planning functionality and tests to SemanticKernel project

  Summary: This commit adds several classes and methods to support planning functionality in the SemanticKernel project. It also adds unit and integration tests for the planning module and the skills involved in creating and executing plans. The main changes are:

  - Added a new class FunctionFlowParser that can parse XML plans created by the Function Flow semantic function. The parser converts the XML string into a SequentialPlan object that can be executed by the planner.
  - Added a new class PlannerConfig that encapsulates the common configuration options for planner instances, such as relevancy threshold, max tokens, and excluded or included functions.
  - Added a new class FunctionFlowPlanner that implements a planner that uses a semantic function to generate a step-by-step plan from a goal, using relevant functions from the kernel.
  - Added a new class SequentialPlan that represents a plan composed of sequential steps. The SequentialPlan class inherits from the Plan class and overrides the InvokeNextStepAsync method to execute the next function in the plan. The SequentialPlan class also has properties for storing the output and result keys of each step.
  - Added a new skill PlannerSkill that can execute a plan using the kernel's skills and context.
  - Added a new email skill that can send emails using the OpenAI completion backend. The email skill demonstrates how to use the context variables and named parameters in the plan steps.
  - Added two new extension methods to the SKContext class: GetFunctionsManualAsync and GetAvailableFunctionsAsync. These methods allow the user to query for functions that match a semantic query and a planner configuration, and to get a manual string for each function.
  - Added several unit tests for the planning functionality of the semantic kernel, covering different scenarios of creating and executing plans using different skills and functions.
  - Added several integration tests for the planning and email skills, covering different scenarios of creating and executing sequential plans that involve summarizing, translating, and sending emails.
  - Updated the Example12_Planning.cs file to demonstrate how to use the planning functionality with a simple web search example and a poetry writing and translating example. The file also demonstrates two different ways of using the planner skill: directly as a skill function, or as a planner class.
  - Imported some skills from the sample skills directory, such as WebSearchEngineSkill and SummarizeSkill.
  - Added some TODO comments and bug reports for the planning module.

Motivation and Context

Description

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows SK Contribution Guidelines (https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
• The code follows the .NET coding conventions (https://learn.microsoft.com/dotnet/csharp/fundamentals/coding-style/coding-conventions) verified with dotnet format
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄

[lemillermicrosoft]

TODO - more testing and integration of Roger's Conditional work -- might need some help here.

[lemillermicrosoft]

Maybe we can just have Conditional stuff be their own Plan implementation that can be added to a SequentialPlan or other.

[lemillermicrosoft]

TODO:

• Merge with conditional work
• Add tests for 'AppendToResult' behavior and add any missing functionality
• Add tests for ensuring outputs
• Design review
• Major cleanup
• More tests

[lemillermicrosoft]

I was on board for getting rid of planner skill, but now I see it more as Removing FunctionFlowRunner and replacing with FunctionFlowParser to take NL XML and convert to a Plan object and then rely on native kernel support for execution. The PlannerSkill can still expose this and use the FunctionFlowPlanner just like a developer could use directly, as well.