Add type `AmazonBedrockImageModelOptions`

[felixarntz]

Description

Currently there's no type for provider specific image model options for Amazon Bedrock.

AI SDK Version

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[lgrammel]

Identify issue type

{
  "evidence": [
    "The description states there is currently no type for provider-specific image model options for Amazon Bedrock.",
    "The requested change is to add a new type, `AmazonBedrockImageModelOptions`."
  ],
  "rationale": "This is an API/type expansion request rather than a report of broken existing behavior.",
  "type": "feature",
  "confidence": "high"
}