**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}`

self.output_encoding = sys.getdefaultencoding()
        self.chunk_size = chunk_size
        self.download_continue_on_fail = download_continue_on_fail
        self.download_num_attempts = download_num_attempts
        self.upload_continue_on_fail = upload_continue_on_fail
        self.upload_num_attempts = upload_num_attempts
    def execute(self, context: Context) -> list[str]:
        
        try:
            orig_start = context["data_interval_start"]
            orig_end = context["data_interval_end"]
        except KeyError:
            orig_start = pendulum.instance(context["execution_date"])
            following_execution_date = context["dag"].following_schedule(context["execution_date"])
            if following_execution_date is None:
                orig_end = None
            else:
                orig_end = pendulum.instance(following_execution_date)
        timespan_start = orig_start
        if orig_end is None:  
            self.log.warning("No following schedule found, setting timespan end to max %s", orig_end)
            timespan_end = pendulum.instance(datetime.datetime.max)
        elif orig_start >= orig_end:  
            self.log.warning("DAG schedule not periodic, setting timespan end to max %s", orig_end)
            timespan_end = pendulum.instance(datetime.datetime.max)
        else:
            timespan_end = orig_end
        timespan_start = timespan_start.in_timezone(timezone.utc)
        timespan_end = timespan_end.in_timezone(timezone.utc)
        source_prefix_interp = GCSTimeSpanFileTransformOperator.interpolate_prefix(