feat: add ai proxy

[floreks]

• Added go/ai-proxy go module
• Added ghcr.io/pluralsh/ai-proxy container
• Added basic chart to deploy it

It does on-the-fly request/response modification to match the configured --provider API. The response format will always match the ollama API format. Provider token when needed can be provided via PLRL_PROVIDER_TOKEN env var or --provider-token flag.

Test Plan

• Locally
• Test on dev

Checklist

• If required, I have updated the Plural documentation accordingly.
• I have added tests to cover my changes.
• I have added a meaningful title and summary to convey the impact of this PR to a user.

[linear]

PROD-2766 openai proxy for autoconfiguring AI for cloud console users

[michaeljguarino]

we should write at least one basic mock test against the endpoint to ensure regressions are covered and make sure there's a gh action to run it

[floreks]

we should write at least one basic mock test against the endpoint to ensure regressions are covered and make sure there's a gh action to run it

Yeah, I also wanted to add some basic tests and gh actions. Should be mostly ready tomorrow.