update: added the implementation for pre_commit and post_commit methods of RestDataConn

[sttk]

This PR adds implementations for two new methods to RedisDataConn: pre_commit and post_commit. Together with force_back, these methods provide a way to maintain data consistency in Redis, even though it lacks a rollback feature, when updating it alongside other databases within a transaction.

Also, I changed the argument for add_force_back from a function pointer to FnMut so that it can capture variables from the environment where the function is defined. The same applies to add_pre_commit and add_post_commit.

[Copilot]

Pull Request Overview

This PR adds implementations for pre_commit and post_commit methods to RedisDataConn to provide better transactional consistency when using Redis alongside other databases. These methods enable Redis operations to be executed at specific points in the transaction lifecycle to maintain data consistency despite Redis's lack of native rollback support.

• Added pre_commit method that executes operations after other database updates but before their commits
• Added post_commit method that executes operations after transaction completion
• Changed function pointer types from fn to FnMut closures to allow capturing environment variables

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