**Description**

Support passing multiple prefixes to `GoogleCloudStorageListOperator` and `GoogleCloudStorageDeleteOperator` operators.

**Use case / motivation**

I have this folder structure in GCS bucket.

```
+-- year={year}
|   +-- month={month}
|       +--day={day}
|           +-- topic={topic1}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           +-- topic={topic2}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           +-- topic={topic3}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           +-- topic={topic4}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           +-- topic={topic5}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           +-- topic={topic6}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           +-- topic={topic7}
|       +--day={day}
|           +-- topic={topic1}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           +-- topic={topic2}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           +-- topic={topic3}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           +-- topic={topic4}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           +-- topic={topic5}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           +-- topic={topic6}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           +-- topic={topic7}
|                 +--file 1
|                 +--file 2
|                 +--file 3
|           ....
```

What I need to achieve is delete one day of objects. For example, I need to delete objects in `year=2020/month=08/day=19`. I can do that easily using `gsutils`. In `gsutil` you can delete them via wild card `gsutil ear=2020/month=08/day=19/*` but using the REST APIs you can't even if you use a prefix. The reason is there is no one prefix to get all the objects inside a folder. I achieved that by using multiple prefixes and for each prefix, I will get the list of objects. Unfortunately, I can't pass more than one prefix to the operators.

**Prefixes used**
- `year=2020/month=08/day=19/topic={topic1}`
- `year=2020/month=08/day=19/topic={topic2}`
- `year=2020/month=08/day=19/topic={topic3}`
- `year=2020/month=08/day=19/topic={topic4}`
- `year=2020/month=08/day=19/topic={topic5}`
- `year=2020/month=08/day=19/topic={topic6}`
- `year=2020/month=08/day=19/topic={topic7}`

"The mutually exclusive parameters. `object_url`, `bucket_name` together "
                    "with `object_name` parameters are present. "
                    "Please provide `object_url` or `bucket_name` and `object_name`."
                )
            if object_url:
                bucket_name, object_name = _parse_gcs_url(object_url)
                kwargs[bucket_name_keyword_arg_name] = bucket_name
                kwargs[object_name_keyword_arg_name] = object_name
                del kwargs[object_url_keyword_arg_name]
            if not object_name or not bucket_name:
                raise TypeError(
                    f"{func.__name__}() missing 2 required positional arguments: "
                    f"'{bucket_name_keyword_arg_name}' and '{object_name_keyword_arg_name}' "
                    f"or {object_url_keyword_arg_name}"
                )
            if not object_name:
                raise TypeError(
                    f"{func.__name__}() missing 1 required positional argument: "
                    f"'{object_name_keyword_arg_name}'"
                )
            if not bucket_name:
                raise TypeError(
                    f"{func.__name__}() missing 1 required positional argument: "
                    f"'{bucket_name_keyword_arg_name}'"
                )
            return func(self, *args, **kwargs)
        return cast(Callable[FParams, RT], _inner_wrapper)
    return cast(Callable[[T], T], _wrapper)
PROVIDE_BUCKET: str = cast(str, None)
class GCSHook(GoogleBaseHook):