[tests] Pipeline test refactor (#14113)
* up
* up
* quantization level refactors.
* style
* up
* up
* use mixins and remove stale attributes
* fixture for the deprecated pipelines
* remove qkv
* remove lergacy for attention processor.
* use pytorch tensors exclusively.
* rejig dodgy test.
* improve how base pipeline output fixture is used.
* rename params.
* up
* use pipeline load api for ip adapter.
* move to flux specific.
* redesign config for caching
* remove eval.
* up
* up
* add a todo note on check_qkv_fusion_matches_attn_procs_length
* nan test in layerwise casting
* proper skipping
* skip properly.
* up
* up
