feat(stablediffusion): Passthrough more parameters to support z-image and flux2 (#7419)

* feat(stablediffusion): Passthrough more parameters to support z-image and flux2

Signed-off-by: Richard Palethorpe <io@richiejp.com>

* chore(z-image): Add Z-Image-Turbo GGML to library

Signed-off-by: Richard Palethorpe <io@richiejp.com>

* fix(stablediffusion-ggml): flush stderr and check errors when writing PNG

Signed-off-by: Richard Palethorpe <io@richiejp.com>

* fix(stablediffusion-ggml): Re-allocate Go strings in C++

Signed-off-by: Richard Palethorpe <io@richiejp.com>

* fix(stablediffusion-ggml): Try to avoid segfaults

Signed-off-by: Richard Palethorpe <io@richiejp.com>

* fix(stablediffusion-ggml): Init sample and easycache params

Signed-off-by: Richard Palethorpe <io@richiejp.com>

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Signed-off-by: Richard Palethorpe <io@richiejp.com>
Co-authored-by: Ettore Di Giacinto <mudler@users.noreply.github.com>