feat: Add convenience function for LlamaGuard Filter

[KavithaSiva]

Context

Closes SAP/ai-sdk-js-backlog#205.

What this PR does and why it is needed

This PR adds a convenience function to enable filter categories for Llama guard filter.

The built filter can then be used in the filtering configuration of the Orchestration client.

[deekshas8]

A suggestion:

Since the default for is false for all properties of the filter, the user only needs to set categories which they want to enable. As such, setting to true seems like a redundant effort. We could allow the user to just pass an array of strings (from union type of all existing properties) and we set them to true.
The pro here would be less typing and less confusion (setting false makes no sense, but this might not very obvious).
The con is it deviates from azure filter a bit where we have a key: value style of input.

[KavithaSiva]

A suggestion:

Since the default for is false for all properties of the filter, the user only needs to set categories which they want to enable. As such, setting to true seems like a redundant effort. We could allow the user to just pass an array of strings (from union type of all existing properties) and we set them to true. The pro here would be less typing and less confusion (setting false makes no sense, but this might not very obvious). The con is it deviates from azure filter a bit where we have a key: value style of input.

I would personally prefer if the user explicitly sets the properties to true as even if it is verbose, it is clear that we are turning some categories on.

buildLlamaGuardFilter({ hate: true, sexual_content: true})  //Very clear
buildLlamaGuardFilter([hate', 'sexual_content']) //Not clear, if we are enabling or disabling the category 

[deekshas8]

buildLlamaGuardFilter([hate', 'sexual_content']) //Not clear, if we are enabling or disabling the category

From my understanding of the filter, you basically can enable a category, the default is false for all the rest categories. What I personally find more confusing is allowing to disable something thats going to be disabled anyway.