Fix - Enhance multigenerator and image generators

[shincap8]

Context

• Nibbler needs more dalle images generated, and there were some models throwing errors.

Changes Made

1. Add more dalle2 and 3 providers.

• This would allow the user to see more images generated by this models.

2. Improve the way several providers are created, passing the model_instance.

• This would allow us to have cleaner code, shorter files and avoid repeating lines.

3. Fix the way SDXLImageProvider parse its response to avoid errors.

• This would allow us to use those models avoiding errors when parsing.

4. Delete SDXLImageProvider with model instance sdxl1 (this is the model remove from huggingface).

• This would allow us not to use a model that we remove from huggingface.

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