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

[fortnern]

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 HDFGroup/hdf5_plugins#216