RPC server that batches requests
Hi @cemlyn007 ,

Thanks for reporting this. Currently this module is under experimental stage.Could you please confirm whether this API can't handle server side batching. Have you tested this ? I know this is under experimental stage and still many features might not be available right now.

 If you want to contribute you may please raise a Pull request for same and Team may happily review it. Thanks!
 This issue is stale because it has been open for 7 days with no activity. It will be closed if no further activity occurs. Thank you. I can confirm that in this [code](https://github.com/tensorflow/tensorflow/blob/master/tensorflow/distribute/experimental/rpc/kernels/rpc_ops.cc) the server does not support server-side batching. I'll have a think about what to do because we are using an older version of TensorFlow (2.8) so we might just decide to implement this as a custom operation.
<details><summary>Click to expand!</summary> 
 
 ### Issue Type

Feature Request

### Have you reproduced the bug with TF nightly?

No

### Source

binary

### Tensorflow Version

2.8.0

### Custom Code

No

### OS Platform and Distribution

_No response_

### Mobile device

_No response_

### Python version

_No response_

### Bazel version

_No response_

### GCC/Compiler version

_No response_

### CUDA/cuDNN version

_No response_

### GPU model and memory

_No response_

### Current Behaviour?

```shell
Currently the only implemented `GrpcServer`, that implements `Server` does not handle server side batching. Perhaps we would want an additional implementation that supports server side batching?

This could be done similar to how SEED-RL wrote their batching layer (https://github.com/google-research/seed_rl/tree/master/grpc).

`Server`: https://github.com/tensorflow/tensorflow/blob/071ef3748e5fdb67a0438f357f37b962edae83e2/tensorflow/python/distribute/experimental/rpc/rpc_ops.py#L51

`GrpcServer`: https://github.com/tensorflow/tensorflow/blob/071ef3748e5fdb67a0438f357f37b962edae83e2/tensorflow/python/distribute/experimental/rpc/rpc_ops.py#L260
```


### Standalone code to reproduce the issue

```shell
N/A
```


### Relevant log output

_No response_</details>