Chore: setup postgres and vector in dockerfile

[StrongMonkey]

This PR should configure postgres and pgvector into otto dockerfile. It will run and use the built-in postgres process if no OTTO8_SERVER_DSN is set.

I ran some test against knowledge ingestion and it works fine.

[StrongMonkey]

Did the following change based on feedback

1. Move the pgvector build stage into a separate step. And copy the necessary artifacts to the final image after it is done.
2. Use cgr.dev/chainguard/postgres:latest-dev as the final image. Noticed that we can't use cgr.dev/chainguard/postgres:latest because it is a distroless image that doesn't come with apk
3. Use /data/postgresql as data store for postgresql so that we can persist database with existing /data volume.

[cjellick]

Looks good. I'd like a rereview by @thedadams or a review by @ibuildthecloud

[ibuildthecloud]

Assuming it works...

[StrongMonkey]

@ibuildthecloud come on where is the trust :)