.NET: [BREAKING] Refactor ChatMessageStore methods to be similar to AIContextProvider and add filtering support

[westey (westey-m)]

Motivation and Context

#2518
#2054

Description

• Refactor ChatMessageStore interface to be more similar to AIContextProvider, to give more certainty as to the data being passed to it, and the circumstances under which that data is passed.
• Add a ChatMessageStore decorator that makes it easy to filter the messages being passed to the ChatMessageStore. This allows us to easily avoid persisting messages from AIContextProviders in the chat history.

AIAgentagent=azureOpenAIClient.GetChatClient(deploymentName).CreateAIAgent(newChatClientAgentOptions{ChatOptions=new(){Instructions="You are a helpful support specialist for Contoso Outdoors. Answer questions using the provided context and cite the source document when available."},AIContextProviderFactory= ctx =>newTextSearchProvider(SearchAdapter,ctx.SerializedState,ctx.JsonSerializerOptions,textSearchOptions),// Since we are using ChatCompletion which stores chat history locally, we can also add a message removal policy// that removes messages produced by the TextSearchProvider before they are added to the chat history, so that// we don't bloat chat history with all the search result messages.ChatMessageStoreFactory= ctx =>newInMemoryChatMessageStore(ctx.SerializedState,ctx.JsonSerializerOptions).WithAIContextProviderMessageRemoval(),});

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the Contribution Guidelines
• All unit tests pass, and I have added new tests where possible
• Is this a breaking change? If yes, add "[BREAKING]" prefix to the title of the PR.