Explore kernel sizes of `refine_*.cu`

[divyegala]

1. refine_device_float_float.cu.o: ~45 MB
2. refine_device_int8_t_float.cu.o: ~26 MB
3. refine_device_uint8_t_float.cu.o: ~26 MB
4. refine_device_half_float.cu.o: ~24 MB

refine_device.cuh seemingly instantiates no kernels, but it is likely instantiating kernels from calling into detail of other files. There may be an opportunity here to consolidate the kernel instantiations to just once.

1. refine and ivf_flat::extend both call into build_index_kernel

   cuvs/cpp/src/neighbors/ivf_flat/ivf_flat_build.cuh

   Lines 514 to 523 in 14d137c

   	build_index_kernel<T, IdxT, LabelT, true>
   	<<<grid_dim, block_dim, 0, stream>>>(new_labels.data(),
   	dataset,
   	candidate_idx,
   	refinement_index->data_ptrs().data_handle(),
   	refinement_index->inds_ptrs().data_handle(),
   	list_sizes_ptr,
   	n_queries * n_candidates,
   	refinement_index->dim(),
   	refinement_index->veclen());

2. refine and ivf_flat::search both call into ivfflat_interleaved_scan kernels
3. refine, ivf_flat::search, and ivf_pq::search all call into postprocess_neighbors_kernel

   cuvs/cpp/src/neighbors/ivf_common.cuh

   Line 153 in 14d137c

   postprocess_neighbors_kernel(IdxT* neighbors_out, // [n_queries, topk]