Pytorch lightning required but not installed for text_normalization
**Describe the bug**

Installing `nemo_toolkit[nemo_text_processing]` does not bring in `pytorch_lightning` but then 
```python
from nemo_text_processing.text_normalization import normalize
```
errors as pytorch_lightning is required to import

**Steps/Code to reproduce bug**

1. on a fresh venv, install `nemo_toolkit[nemo_text_processing]` 
2. run `from nemo_text_processing.text_normalization import normalize`
3. See error

**Expected behavior**

If text processing requires pytorch_lightning it should be installed as a requirement
