[code_review] Try prompting for each hunk in the patch

[marco-c]

Giving the patch and the hunk separately, so we can let the LLM focus on the specific hunk and we don't need to then try to match comments and hunks.

Something like:

You are an expert reviewer for the Mozilla Firefox source code. You reviewed the given patch and provided a constructive code review comment for the hunk.

### Patch:
{PATCH}

### Hunk:
{HUNK}