Remove deprecated FunctionCallback references

[ilayaperumalg]

From 1.0.0-M6, The org.springframework.ai.model.function.FunctionCallback and related classes were deprecated and ToolCallback is the preferred choice going forward.

This issue addresses removal of the deprecated FunctionCallback usages and replace them with tool specific implementations.

[apollo-de]

Builder toolCallbacks(List<FunctionCallback> functionCallbacks);

in class ToolCallingChatOptions.Builder should be changed in particular.

[ilayaperumalg]

@apollo-de Yes, please check the changes here