### 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
self.add_verify_options(collection_parser, parents=[common, collections_path])
        
        role = type_parser.add_parser('role', help='Manage an Ansible Galaxy role.')
        role_parser = role.add_subparsers(metavar='ROLE_ACTION', dest='action')
        role_parser.required = True
        self.add_init_options(role_parser, parents=[common, force, offline])
        self.add_remove_options(role_parser, parents=[common, roles_path])
        self.add_delete_options(role_parser, parents=[common, github])
        self.add_list_options(role_parser, parents=[common, roles_path])
        self.add_search_options(role_parser, parents=[common])
        self.add_import_options(role_parser, parents=[common, github])
        self.add_setup_options(role_parser, parents=[common, roles_path])
        self.add_info_options(role_parser, parents=[common, roles_path, offline])
        self.add_install_options(role_parser, parents=[common, force, roles_path])
    def add_download_options(self, parser, parents=None):
        download_parser = parser.add_parser('download', parents=parents,
                                            help='Download collections and their dependencies as a tarball for an '
                                                 'offline install.')
        download_parser.set_defaults(func=self.execute_download)
        download_parser.add_argument('args', help='Collection(s)', metavar='collection', nargs='*')
        download_parser.add_argument('-n', '--no-deps', dest='no_deps', action='store_true', default=False,
                                     help="Don't download collection(s) listed as dependencies.")
        download_parser.add_argument('-p', '--download-path', dest='download_path',
                                     default='./collections',
                                     help='The directory to download the collections to.')
        download_parser.add_argument('-r', '--requirements-file', dest='requirements',
                                     help='A file containing a list of collections to be downloaded.')
        download_parser.add_argument('--pre', dest='allow_pre_release', action='store_true',
                                     help='Include pre-release versions. Semantic versioning pre-releases are ignored by default')
    def add_init_options(self, parser, parents=None):