feat: Add usage field to image generation responses

[the-fermi-paradox]

What:

• New Feature

Description:

Adds the 'usage' field which is supplied by OpenAI in Image creation responses.

Related:

#569

[abikali]

We worked on this together #571

I've included the usage for the variation and edit as well

[the-fermi-paradox]

We certainly did not work on this together. I'm not sure what you mean.

[abikali]

You misunderstood me.

I meant we worked on the same feature at the same time.
We created the same feature PR in a 20 mins difference, which technically means we worked on the same feature together.

Apologies for the wording/misunderstanding, getting late here, heading to sleep.

[iBotPeaches]

looks good! Will merge in the morning.

[SeriousOne]

Will we get a new version today (v0.10.4)?

[abikali]

This PR only returns usage on the Create image endpoint, whereas OpenAI returns the usage on the Create, Edit and Variation endpoint. see https://platform.openai.com/docs/api-reference/images/object

I already handled these endpoints in my PR #571

If you want to merge this PR, I can push my changes here, but don't really see the reason for it.
@iBotPeaches

[iBotPeaches]

Probably first time I've ever seen the same-ish PR worked on by two different people around the same time. Should free up in an hour to take a look at all of this again and do some merging.

[the-fermi-paradox]

@iBotPeaches Haha, yeah, it was bizarre to me too.