Agnostic_baker: Fix manual command

What

Fixing a bug with the man command on the ./octez-experimental-agnostic-baker binary.

Why

Because currently the command does not display the baking commands:

./octez-experimental-agnostic-baker man

... (help information)

Access the documentation:

  man [<keyword>...]
    Print documentation of commands.

Commands for editing and viewing the client's config file:

  config show
    Show the current config (config file content + command line arguments) or the mockup config files if
    `--mode mockup` is specified.

  config reset
    Reset the config file to the factory defaults.

  config update
    Update the config based on the current cli values.

  config init
    Create config file(s) based on the current CLI values.

Miscellaneous commands:

  list understood protocols
    List the protocol versions that this client understands.

How

By calling the main running function with the man argument, but without any plugin, because there is no need for it in this case. This is done by refactoring the commands to potentially not do anything in case no plugin is provided.

Manually testing the MR

You can see the before case in the section above. After this MR, you should be able to see the baking commands (e.g. run with local node etc.) with their correct descriptions:

./octez-experimental-agnostic-baker man

... (help information)

Access the documentation:

  man [<keyword>...]
    Print documentation of commands.

Commands for editing and viewing the client's config file:

  config show
    Show the current config (config file content + command line arguments) or the mockup config files if
    `--mode mockup` is specified.

  config reset
    Reset the config file to the factory defaults.

  config update
    Update the config based on the current cli values.

  config init
    Create config file(s) based on the current CLI values.

Commands related to the agnostic baker daemon.:

  run with local node <node_data_path> [<baker>...]
    Launch the baker daemon.

  run remotely [<baker>...]
    Launch the baker daemon using RPCs only.

  run vdf
    Launch the VDF daemon

Miscellaneous commands:

  list understood protocols
    List the protocol versions that this client understands.

You can also see more information is being output-ed if you run ./octez-experimental-agnostic-baker man --verbosity 3.

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR