Feature: FuncTaskState Support

[wt-better]

Saga is a distributed transaction processing mode used to ensure consistency in distributed systems.The state machine mode of saga implemented in seata java, it needs to be support in seata go.

Each node of the state machine is declared as a state, and the state machine process is composed of different types of nodes.The ServiceTaskState represents an executable node. Historically, we have supported GrpcServiceTaskState. but Local func calls are the most frequent in golang, so we need to support TaskState of Func type.

@see ：pkg/saga/statemachine/statelang/state/task_state.go

[wt-better]

There has been one history implementation, corresponding to the branch: feature/saga, but the details need to be completed. you can develop on this branch.

[marsevilspirit]

asign me pls