The CLI --help command doesn't work

**Intended outcome:**

I was trying to figure out how to use the `client:codegen` subcommand. It directed me to use the `--help` option and no matter where I place it, I'm unable to get help output. I expected to see information about the command's flags, but instead received an error about a plugin.

**Actual outcome:**

```
> yarn apollo client:codegen
yarn run v1.22.17
$ /home/nirvdrum/dev/workspaces/taskerator/node_modules/.bin/apollo client:codegen
› Error: Missing required flag:
› --target TARGET Type of code generator to use (swift | typescript | flow | scala | json | json-modern (exposes raw json types))
› See more help with --help
error Command failed with exit code 2.
```

```
> yarn apollo client:codegen --help
yarn run v1.22.17
$ /home/nirvdrum/dev/workspaces/taskerator/node_modules/.bin/apollo client:codegen --help
TypeError: plugin_help_1.getHelpClass is not a function
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

> yarn apollo --help client:codegen
yarn run v1.22.17
$ /home/nirvdrum/dev/workspaces/taskerator/node_modules/.bin/apollo --help client:codegen
TypeError: plugin_help_1.getHelpClass is not a function
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

> yarn apollo --help
yarn run v1.22.17
$ /home/nirvdrum/dev/workspaces/taskerator/node_modules/.bin/apollo --help
TypeError: plugin_help_1.getHelpClass is not a function
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
```

**How to reproduce the issue:**

1. Create a new JS project.
2. Install _apollo_ as a dev dependency (e.g., `yarn add -D apollo`)
3. Run help command: `yarn apollo --help`

Please note that the issue can be reproduced using `npm` instead of `yarn`.

**Versions**

Apollo: 2.33.9

Start by reproducing the failure with `yarn apollo --help` and `yarn apollo client:codegen --help` in a new project using Apollo 2.33.9. Trace the CLI help entry point and the `plugin_help_1.getHelpClass` error; done means the general and subcommand help commands print their flag information without the plugin error.

Written by the indexing model from the issue text.