Feature request: Create public interfaces to H5Z_pipeline, H5Z_can_apply, and H5Z_set_local

This would allow use of the HDF5 filter pipeline mechanism independent of an HDF5 file. In particular, this would allow filters to embed nested filters in cases where the simple 1-D pipeline scheme can't be made to work, while still making use of the HDF5 filter machinery for the nested filters. See https://github.com/HDFGroup/hdf5_plugins/issues/216