refactor: add the main cli entry point struct Command{} and simplify main()

[zyy17]

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Refer to a related PR or issue link (optional)

What's changed and what's your intention?

The parsing entry of the current command line is a bit messy and I think we need a cleaner and more unified entry.

• Add the Command{} struct: Unify all the cli options, including subcommand and global options. When we load the cli option, use Command::parse();

• Make the main() cleaner by using the following sub-functions:

  • Add setup_human_panic();
  • Add start() to load the options and start the service;

• Rename CliOptions to GlobalOptions;

Reference: uv has a clean entry point.

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR does not require documentation updates.

[codecov]

Codecov Report

Attention: Patch coverage is 52.50000% with 38 lines in your changes are missing coverage. Please review.

Project coverage is 85.34%. Comparing base (1b58622) to head (65a72c4).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3850      +/-   ##
==========================================
- Coverage   85.61%   85.34%   -0.28%     
==========================================
  Files         952      952              
  Lines      163232   163204      -28     
==========================================
- Hits       139753   139281     -472     
- Misses      23479    23923     +444     

[tisonkun]

Good refactor! Thank you.