* Add support for negative padding

* Use std::bind in pad builder check

* Add support for negative padding in CPU backend

* Updated kernel to do pad+slice

* Remove type conversion warnings

* Fix review comments

* Remove interior padding from core op and interpreter stuff

* Update backends other than GPU for retirement of padding_interior

* Skeleton of support for edge/reflect padding

* Post-merge cleanup

* Attempt reference implementation for EDGE.

* Fix the edge-padding reference, and add some unit tests

* Implement REFLECT padding ref; add tests

* Fixes to the CPU stuff so it compiles now

* Fix test

* Add support for different pad modes

* Restore a stub get_padding_interior function, and tweak some stale comments

* Update ONNX importer to not supply interior padding value; add checks for padding-too-small for EDGE and REFLECT

* Typo

* Bop a warning

* Attempt fix to INTELGPU backend

* Attempt another fix to INTELGPU backend

* Fix pyapi

* Style apply

* Add support for padding modes

* Remove unnecesary node validation checks

* Remove tests for minimal reflect and edge pad

* Remove commented tests

* Remove unnecesary Asserts

* Little update of pad documentation

* Monospace for pad_mode options

* Revert "Remove tests for minimal reflect and edge pad"

This reverts commit 81e4787ea47195b832cab1452dde698bc05776fe.

* Revert "Remove unnecesary node validation checks"

This reverts commit 7e68db7564f3c9b1fd40e7db1d1bda4e0677cad9.

* Test only spatial dims

* axis -> spatial axis

* Fix typo

* Style check

* Update test

* Add CoordinateDiff include

* Remove pad_mode from tree visualization

* Convert padding into NVShape

* Skip failing tests on GPU

* Revert mode change

* Remove merge artifact

* Rename pad kernel into pad_ref