Pass `USERNAME` to Redis `connection_kwargs`

[joachimBurket]

Problem Statement
The username defined in the cache options is not passed to the connection kwargs.

I'm connecting to a Sentinel cluster with the following cache parameters:

CACHES = {
    'default': {
        'BACKEND': 'django_redis.cache.RedisCache',
        'LOCATION': 'redis://redis6.local/0',
        'OPTIONS': {
            'CLIENT_CLASS': 'django_redis.client.SentinelClient',
            'USERNAME': 'my-redis-user',
            'PASSWORD': 'my-very-long-redis-password',
            'SENTINEL_KWARGS': {
                'username': 'my-sentinel-user',
                'password': 'my-very-long-sentinel-password',
            },
            'SENTINELS': [
                ('redis6a.local', 26379), ('redis6b.local', 26379), ('redis6c.local', 26379)
            ],
        }
    }
}

So the SentinelConnectionFactory is used.

The SENTINEL_KWARGS are passed to the Sentinel objects, but the USERNAME is not passed to the connection_kwargs param.

Describe the solution you'd like
The make_connection_params() method should get the USERNAME from the options.

def make_connection_params(self, url):

    kwargs = {
        "url": url,
        "parser_class": self.get_parser_cls(),
    }

    # ADD THIS
    username = self.options.get("USERNAME", None)
    if username:
        kwargs["username"] = username

    password = self.options.get("PASSWORD", None)
    if password:
        kwargs["password"] = password

    # [...]

    return kwargs

I'm not sure if there are other cases where the USERNAME should be passed to the Sentinel or Redis objects. Maybe in the ConnectionFactory's get_connection_pool() method?

I can start a merge request with that.