Add command to delete saved wallet config

**Describe the enhancement**

The wallet config command stores the configuration information for a wallet in the `config.toml` file which is then reused on all subsequent wallet operations. However, there is no way to remove/delete a wallet configuration even when the wallet may no longer be needed.

Adding a command to delete a saved wallet configuration will help reduce the number of redundant wallet configurations and improve the amount of data saved in the config file.

**Use case**

- This will allow users to clean up the wallet config file and remove redundant wallet configs.

从现有的 wallet config 命令及其使用的 config.toml 处理逻辑开始。跟踪已保存的 wallet 配置如何为后续的 wallet 操作进行选择，然后将“完成”定义为：有一个命令可以删除所选配置，并阻止再次使用该配置。

由索引模型根据 Issue 内容生成。