Consolidate and integrate GPU PI11 (de/gridding) processing functions

Gridding and degridding functions are critical to multiple future SDP imaging pipelines and are therefore ideal candidates for developing as initial core functions of an SDP processing function library that we can take forward and evolve during construction as a product that provides the building blocks for performant, scalable SDP pipelines.

• Address technical debt in gridding and degridding processing functions so that either the following are met or there is a clearly documented route forward to achieve:
  • All code merged into the main / master branch so that it is easily discoverable.
  • Code is provided with well defined versioning and a associated changelog.
  • Where appropriate, release pages are created providing links to documentation, packaged, versioned artefacts, change notes, targeted at the intended user of the code - in this case processing function and pipeline developers.
  • Code must publish (API, user, and developer) documentation and doing so should be automated as part of the CI/CD pipeline.
  • Code should be supported by a number tests that validate behaviour, functionality and, were appropriate and feasible performance. Wherever possible tests should be automated and run on a regular basis (such as for each commit and merge request).
  • Published, versioned artefacts should be stored in a suitable artefact repo such that if someone is using the code they are able to easily refer to the exact version being used and where they obtained it. This is important to be able to track and identify issues.
• Review of outcome of SP-1826 against technical debt improvements in the gridding code and decide on (and where possible implement) a route towards integrating the de/gridding code as a SDP Processing function library.
• Fix outstanding issues related to the performance and/or quality of the images produced (such as low level non-gaussian artefacts) - supported by and forming the basis of future regression tests.