Add universal noise and optional denoiser noise inputs (#9044)

* add universal noise and optional denoiser noise inputs

* Document scheduler parity limitations

* Clarify external noise integration rules

* chore: typegen

* Fix external noise handling regressions

* chore: typegen

* Fix stale FLUX.2 scheduler mu test

* chore: typegen

* chore: typegen

* chore: typegen

* Fold universal noise into noise node

* Address PR review cleanup comments

* remove num_channels from noise shape validation

* restore internal piping for cogview and sd3 channels

* chore: ruff

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Co-authored-by: Alexander Eichhorn <alex@eichhorn.dev>
Co-authored-by: dunkeroni <dunkeroni@gmail.com>