### 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
galaxy_type = 'collection' if parser.metavar == 'COLLECTION_ACTION' else 'role'
        init_parser = parser.add_parser('init', parents=parents,
                                        help='Initialize new {0} with the base structure of a '
                                             '{0}.'.format(galaxy_type))
        init_parser.set_defaults(func=self.execute_init)
        init_parser.add_argument('--init-path', dest='init_path', default='./',
                                 help='The path in which the skeleton {0} will be created. The default is the '
                                      'current working directory.'.format(galaxy_type))
        init_parser.add_argument('--{0}-skeleton'.format(galaxy_type), dest='{0}_skeleton'.format(galaxy_type),
                                 default=C.GALAXY_COLLECTION_SKELETON if galaxy_type == 'collection' else C.GALAXY_ROLE_SKELETON,
                                 help='The path to a {0} skeleton that the new {0} should be based '
                                      'upon.'.format(galaxy_type))
        obj_name_kwargs = {}
        if galaxy_type == 'collection':
            obj_name_kwargs['type'] = validate_collection_name
        init_parser.add_argument('{0}_name'.format(galaxy_type), help='{0} name'.format(galaxy_type.capitalize()),
                                 **obj_name_kwargs)
        if galaxy_type == 'role':
            init_parser.add_argument('--type', dest='role_type', action='store', default='default',
                                     help="Initialize using an alternate role type. Valid types include: 'container', "
                                          "'apb' and 'network'.")
    def add_remove_options(self, parser, parents=None):