Virtual pipeline parallel support for LoRA in NLPAdapterModelMixin
# What does this PR do ?

Corrects handling of `model.virtual_pipeline_model_parallel_size` > 1 alongside `model.peft.peft_scheme=lora`; before this fix adapters are attached only to the first virtual pipeline chunk.

**Collection**: nlp

# Changelog 
- Replace parameter-based check for first pipeline stage with `parallel_state.is_pipeline_first_stage()` to account for virtual pipeline stage
- Alter various methods (`_get_all_keys`, `_check_and_add_peft_cfg`, `setup_optimizer_param_groups`, `set_tunable_base_params`, `tie_weights`, `get_peft_state_dict`, `load_state_dict`) to apply LoRA changes to all layers rather than only those in the first chunk and to write and read checkpoints correctly when virtual pipeline parallel is used

# Usage
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```python
# Add a code snippet demonstrating how to use this 
```

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# Additional Information
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