### Summary

To reproduce, run these commands where `ns.col` is the name of a collection you do not have installed and the value of `-p` is a valid collection path that exists:

`ansible-galaxy collection list ns.col -p collections/`
`$?`

The output of $? on devel is 0, but since the collection wasn't found it should be 1. The same issue exists for listing specific roles that do not exist.

To fix:
1. [This method](https://github.com/ansible/ansible/blob/stable-2.14/lib/ansible/cli/galaxy.py#L1494-L1502) needs to return the correct exit code from `execute_list_role` and `execute_list_collection`.

2. `execute_list_collection` and `execute_list_role` will need to be fixed to return 1 if a collection/role was requested and not found.
For example, on [this line ](https://github.com/ansible/ansible/blob/stable-2.14/lib/ansible/cli/galaxy.py#L1680) add
```python
        if not collection_found and collection_name:
            return 1
```

3. Add a new test to [this file](https://github.com/ansible/ansible/blob/stable-2.14/test/integration/targets/ansible-galaxy-collection/tasks/list.yml), similar to [this one](https://github.com/ansible/ansible/blob/stable-2.14/test/integration/targets/ansible-galaxy-collection/tasks/list.yml#L111-L116) that lists a single collection that does not exist. Then add an assert task following it to test that the command result's rc is 1.

4. Add a `bugfixes` [changelog fragment](https://docs.ansible.com/ansible/latest/community/development_process.html#creating-a-changelog-fragment).

### Issue Type

Bug Report

### Component Name

ansible-galaxy

### Ansible Version

```console
$ ansible --version
ansible [core 2.15.0.dev0]
```


### Configuration

```console
# if using a version older than ansible-core 2.12 you should omit the '-t all'
$ ansible-config dump --only-changed -t all
```


### OS / Environment

N/A

### Steps to Reproduce

<!--- Paste example playbooks or commands between quotes below -->
```bash (paste below)
ansible-galaxy collection list ns.col -p collections/
$?
```

### Expected Results

1

### Actual Results

```console
0
```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
''' create an options parser for bin/ansible '''
        super(GalaxyCLI, self).init_parser(
            desc="Perform various Role and Collection related operations.",
        )
        
        common = opt_help.argparse.ArgumentParser(add_help=False)
        common.add_argument('-s', '--server', dest='api_server', help='The Galaxy API server URL')
        common.add_argument('--token', '--api-key', dest='api_key',
                            help='The Ansible Galaxy API key which can be found at '
                                 'https://galaxy.ansible.com/me/preferences.')
        common.add_argument('-c', '--ignore-certs', action='store_true', dest='ignore_certs', help='Ignore SSL certificate validation errors.', default=None)
        common.add_argument('--timeout', dest='timeout', type=int,
                            help="The time to wait for operations against the galaxy server, defaults to 60s.")
        opt_help.add_verbosity_options(common)
        force = opt_help.argparse.ArgumentParser(add_help=False)
        force.add_argument('-f', '--force', dest='force', action='store_true', default=False,
                           help='Force overwriting an existing role or collection')
        github = opt_help.argparse.ArgumentParser(add_help=False)
        github.add_argument('github_user', help='GitHub username')
        github.add_argument('github_repo', help='GitHub repository')
        offline = opt_help.argparse.ArgumentParser(add_help=False)
        offline.add_argument('--offline', dest='offline', default=False, action='store_true',
                             help="Don't query the galaxy API when creating roles")
        default_roles_path = C.config.get_configuration_definition('DEFAULT_ROLES_PATH').get('default', '')