No help text for the "help" sub-command when in a directory containing snapcraft.yaml

[林博仁(Buo-ren, Lin)]

```
$ snapcraft --version
snapcraft 8.2.5

$ snapcraft help help
Usage: snapcraft [options] command [args]...
Try 'snapcraft -h' for help.

Error: command 'help' not found to provide help for
```

I was originally wanna check whether there an option to specify which base snap to provide the help text of the autotools plugin.

[林博仁(Buo-ren, Lin) (buo-ren-lin)]

Wait... the help text is indeed implemented, however, the problem can be reproduced on a different working directory!!?

```
brlin@brlin-fw13:~/文件$ snapcraft help help
Usage: snapcraft [options] command [args]...
Try 'snapcraft -h' for help.

Error: command 'help' not found to provide help for

brlin@brlin-fw13:~/文件$ cd nano-snap
brlin@brlin-fw13:~/文件/nano-snap$ snapcraft help help
Usage: snapcraft help [OPTIONS] <topic>

  Obtain help for a certain topic, plugin or command.

  The <topic> can either be a plugin name or one of:

      - topics
      - plugins
      - sources

  Examples:
      snapcraft help topics
      snapcraft help plugins
      snapcraft help sources
      snapcraft help go
      snapcraft help go --base core18
      snapcraft help build

Options:
  --devel Show more details for snapcraft developers
  --base [core18|core20] Show help for specific base
  -h, --help Show this message and exit.
brlin@brlin-fw13:~/文件/nano-snap$ locale
LANG=zh_TW.UTF-8
LANGUAGE=zh_TW:zh
LC_CTYPE="zh_TW.UTF-8"
LC_NUMERIC="zh_TW.UTF-8"
LC_TIME="zh_TW.UTF-8"
LC_COLLATE="zh_TW.UTF-8"
LC_MONETARY="zh_TW.UTF-8"
LC_MESSAGES="zh_TW.UTF-8"
LC_PAPER="zh_TW.UTF-8"
LC_NAME="zh_TW.UTF-8"
LC_ADDRESS="zh_TW.UTF-8"
LC_TELEPHONE="zh_TW.UTF-8"
LC_MEASUREMENT="zh_TW.UTF-8"
LC_IDENTIFICATION="zh_TW.UTF-8"
LC_ALL=
```

[林博仁(Buo-ren, Lin) (buo-ren-lin)]

It appears that the `snapcraft help help` command will fail/behave differently if a snapcraft yaml file is found:

```
brlin@brlin-fw13:~/文件/not-snap$ ls
brlin@brlin-fw13:~/文件/not-snap$ snapcraft help help
Usage: snapcraft [options] command [args]...
Try 'snapcraft -h' for help.

Error: command 'help' not found to provide help for

brlin@brlin-fw13:~/文件/not-snap$ touch snapcraft.yaml
brlin@brlin-fw13:~/文件/not-snap$ snapcraft help help
Traceback (most recent call last):
  File "/snap/snapcraft/11627/bin/snapcraft", line 8, in <module>
    sys.exit(main())
  File "/snap/snapcraft/11627/lib/python3.10/site-packages/snapcraft/application.py", line 361, in main
    return app.run()
  File "/snap/snapcraft/11627/lib/python3.10/site-packages/craft_application/application.py", line 488, in run
    dispatcher = self._get_dispatcher()
  File "/snap/snapcraft/11627/lib/python3.10/site-packages/snapcraft/application.py", line 184, in _get_dispatcher
    base = yaml_data.get("base")
AttributeError: 'NoneType' object has no attribute 'get'
brlin@brlin-fw13:~/文件/not-snap$ rm snapcraft.yaml
brlin@brlin-fw13:~/文件/not-snap$ snapcraft init
Created 'snap/snapcraft.yaml'.
Go to https://docs.snapcraft.io/the-snapcraft-format/8337 for more information about the snapcraft.yaml format.
brlin@brlin-fw13:~/文件/not-snap$ snapcraft help help
Usage: snapcraft help [OPTIONS] <topic>

  Obtain help for a certain topic, plugin or command.

  The <topic> can either be a plugin name or one of:

      - topics
      - plugins
      - sources

  Examples:
      snapcraft help topics
      snapcraft help plugins
      snapcraft help sources
      snapcraft help go
      snapcraft help go --base core18
      snapcraft help build

Options:
  --devel Show more details for snapcraft developers
  --base [core18|core20] Show help for specific base
  -h, --help Show this message and exit.

```

[Callahan Kovacs (mr-cal)]

I can confirm this behavior. We probably need to catch for `help` here similar to catching for `version`: https://github.com/canonical/snapcraft/blob/99387d281624421b613c3c9dc6d3627092fef74b/snapcraft/application.py#L206

We may also need to update these to point to the new craft-application commands:
https://github.com/canonical/snapcraft/blob/99387d281624421b613c3c9dc6d3627092fef74b/snapcraft/cli.py#L37

[Callahan Kovacs (mr-cal)]

Tracking internally with CRAFT-2904