Changing AgentState.response -> AgentState.messages

[splunk-dtaborski]

No description provided.

[szykol]

looks like a couple of formatting changes are included in this PR as well, make sure you're using ruff

[szykol]

for example formatting a file: uv run ruff format --force-exclude splunklib/ai/base_agent.py.

sorting imports: uv run ruff check --fix --force-exclude --select=I001 --exit-zero --no-cache

though IIRC not all files in the repo are properly formatted yet, we wanted to make it after merging to public repo, so for the time being make sure to format only the files you're changing.

[szykol]

We'll consider adding makefile targets for formatting to make lifes easier