Add entrypoints

[MattWellie]

Fixes

• the separate scripts that make up the Talos workflow are being referenced by paths to scripts inside the container

Proposed Changes

• adds a console_script entrypoint for each separate script
• I've split out the entrypoint within those scripts to have a cli-accessible main method (where CLI arguments are parsed), and a code-accessible main method (so that I can add a simpler single-step runner for easier use)
• this PR is almost entirely moving things around, not changing behaviour
• This will require a PR in prod-pipes

Checklist

• [ ] Related Issue created
• [ ] Tests covering new change
• [ ] Linting checks pass

[MattWellie]

like checkpointing changes

This was bundled in just to reduce the number of CLI args, a slight behaviour change. We're doing everything in a container and throwing the checkpoint away, so removing the need to pass a specific path. This behaviour might return when we need to support other environments where they might want to recover from a partially-complete run using a persisted checkpoint

(passing a path specifically in the attached storage drive was also supposed to help the out-of-space hail issue, but it wasn't effective)