Lazy data files resolution
Related to discussion at https://github.com/huggingface/datasets/pull/6255

this makes this code run in 2sec instead of >10sec

```python
from datasets import load_dataset

ds = load_dataset("glue", "sst2", streaming=True, trust_remote_code=False)
```

For some datasets with many configs and files it can be up to 100x faster.
This is particularly important now that some datasets will be loaded from the Parquet export instead of the scripts.

The data files are only resolved in the builder `__init__`. To do so I added DataFilesPatternsList and DataFilesPatternsDict that have `.resolve()` to return resolved DataFilesList and DataFilesDict