Summarization Pipeline not outputting both text and token_ids
### System Info

- Python version: 3.9.15
- Huggingface_hub version: 0.10.1
- PyTorch version (GPU?): 1.12.1 (False)
- Tensorflow version (GPU?): not installed (NA)
- Flax version (CPU?/GPU?/TPU?): not installed (NA)
- Jax version: not installed
- JaxLib version: not installed
- Using GPU in script?: No
- Using distributed or parallel set-up in script?: No

### Who can help?

@Narsil

### Information

- [ ] The official example scripts
- [X] My own modified scripts

### Tasks

- [ ] An officially supported task in the `examples` folder (such as GLUE/SQuAD, ...)
- [X] My own task or dataset (give details below)

### Reproduction

```python
from transformers import pipeline

summariser = pipeline("summarization", model="sshleifer/distilbart-cnn-12-6")
output = summariser("this is a test input", return_text=True, return_tensors=True)
print(output)
```
Returns (ignoring length warning message):
```
[{'summary_token_ids': tensor([   2,    0,   42,   16,   10, 1296, 8135, 8135,   31,    5, 2730,    9,
            42, 1566,  479,  152,   16,   45,    5,   78,   86,   52,  348,  450,
            42, 1905,   11,   10, 1296,  422,   30,    5, 2730,    4,   42,   16,
             5,   78,    9,   63,  761,    4,  152,   16,    5,  200,    9,   10,
           651,    9, 1296, 1237,   30,    5, 7601,    9,    5, 1040,  479,    2])}]
```


### Expected behavior

According to the `SummarizationPipeline` [documentation](https://huggingface.co/docs/transformers/main_classes/pipelines#transformers.SummarizationPipeline.__call__) I would expect a list of dictionaries where each dictionary has both `summary_text` and `summary_token_ids` elements. Instead, only one is returned, even though both `return_text=True` and  `return_tensors=True` in the call to the summariser.

I have done a little digging and think it's coming from the way these arguments are handled. In the `_sanitize_parameters` method [here](https://github.com/huggingface/transformers/blob/30d8919ab13dcc212cb00fbb4d3e969aee6c3fc5/src/transformers/pipelines/text2text_generation.py#L73), the `postprocess_params["return_type"]` gets set to either ` ReturnType.TENSORS` or ` ReturnType.TEXT` (or a different `return_type` specified as an input arg).

 The `postprocess` method of the `Text2TextGenerationPipeline` [here](https://github.com/huggingface/transformers/blob/30d8919ab13dcc212cb00fbb4d3e969aee6c3fc5/src/transformers/pipelines/text2text_generation.py#L195) then takes the `return_type` arg, but can only ouput either the `summary_text` or `summary_token_ids`, and not both.

I could have a go at raising a PR for this if you'd like.

Many thanks.



Realised that this has been addressed in another issue, apologies.