autogenertion of pipeline templates

[dkazanc]

The pipeline templates that we provide to users (and for production testing) should be automatically generated to avoid manual updating for every release.
The high level syntax such as this can be used:

- method: standard_tomo
  module_path: httomo.data.hdf.loaders
- method: find_center_vo
  module_path: httomolibgpu.recon.rotation
- method: remove_outlier
  module_path: httomolibgpu.misc.corr
....

The pipeline auto-generation script will use the latest templates from httomo-backends in order to build up the full pipeline.