Feat: Stable diffusion v3

[narengogi]

Description:

• Added support for Stable diffusion v2Beta route with support for 3 text-to-image models. Core, Ultra and 3Large
• Same support in Bedrock also
• Added a new parameter in provider config transformToFormData using this to transform to form data
• Added the new transformer for form data also

Related Issues: (optional)

• https://github.com/Portkey-AI/gateway/issues/616

Testing Done:

• [X] Tested to make sure SDXL-1 is working
• [X] verified error and success response transforms
• [X] verified by making requests to /audio/translations and /transcriptions