Add optional parameters to `PoseEstimation`

[vigji]

As described in https://github.com/catalystneuro/neuroconv/issues/915, I would need to pass over a name value to PoseEstimation to support multiple DLC pose estimations in the same nwb file.

I am currently fixing it by piping an optional dictionary of additional kwargs from the args in this way:

def _write_pes_to_nwbfile(
   nwbfile,
   animal,
   df_animal,
   scorer,
   video,  # Expects this to be a tuple; first index is string path, second is the image shape as "0, width, 0, height"
   paf_graph,
   timestamps,
   exclude_nans,
   **optional_kwargs,
):  
   ...

   pe = PoseEstimation(
       pose_estimation_series=pose_estimation_series,
       description="2D keypoint coordinates estimated using DeepLabCut.",
       original_videos=[video[0]],
       # TODO check if this is a mandatory arg in ndx-pose (can skip if video is not found_
       dimensions=[list(map(int, video[1].split(",")))[1::2]],
       scorer=scorer,
       source_software="DeepLabCut",
       source_software_version=deeplabcut_version,
       nodes=[pes.name for pes in pose_estimation_series],
       edges=paf_graph if paf_graph else None,
       **optional_kwargs,
   )

If you would be open to support this fix, I can submit a new PR or add this solutions as well to #23, as you prefer!