[FEATURE] Support additional or custom paint params

[zavan]

Scope check

• This is core LLM communication (not application logic)
• This benefits most users (not just my use case)
• This can't be solved in application code with current RubyLLM
• I read the Contributing Guide

Due diligence

• I searched existing issues
• I checked the documentation

What problem does this solve?

Right now the only supported options for the paint method are:

ruby_llm/lib/ruby_llm/image.rb

Lines 34 to 39 in 1b720ba

	def self.paint(prompt, # rubocop:disable Metrics/ParameterLists
	model: nil,
	provider: nil,
	assume_model_exists: false,
	size: '1024x1024',
	context: nil)

However OpenAI allows:

Of these, only size is supported right now.

I am mostly interested in the quality param.

Proposed solution

One of:
a. Allow passing arbitrary options to paint.
b. Add a with_params for images, like we have for chats.
c. Add some specific options to the paint method.

Why this belongs in RubyLLM

These options are important and useful, RubyLLM should support provider specific image generation params just like it does for chats.