Improve CLI logging messages (e.g. for incremental builds)

We should improve the CLI logging messages e.g. in the following cases:

- timing: we should add how long a step has taken (e.g. 50ms to generate 20 documents)
- This should also provide a summary of how time is spent in different remark plugins etc
- Adjust log messages for incremental builds based on file watching. (Currently the log messages indicate that all documents have been re-generated even though just a single file has changed)
- The log messages should also indicate when using cache from file system

Ideally we can even easily test the wanted behaviour above in unit tests.

该 issue 未指定文件、入口点或现有测试。首先定位 CLI 日志记录、增量文件监视、缓存和 remark-plugin 的路径，然后检查单元测试如何覆盖它们。完成的标准是：日志报告各步骤的耗时和摘要，识别增量变更以及文件系统缓存的使用情况，并且有针对所请求行为的测试。

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