Update starters to use new /conf structure

[DimedS]

Motivation and Context

In previous updates #2856 and #2884, we modified the structure of the /conf folder to

├── conf
    └── base
	├── catalog_{pipeline-name}.yml          #blank files
	└── parameters_{pipeline-name}.yml       #blank files
        ├── catalog.yml          #blank files   
	└── parameters.yml       #blank files

This PR aims to align the structure of the starters accordingly. Notably, there are no starters with a 'catalog' folder, and only the spaceflights starter contains a 'parameters' folder. This change involves moving two YML files for the spaceflights starter from 'parameters' folder and adding 'parameters_' to the beginning of the filenames.

How has this been tested?

The modifications have been tested with the 'pipeline create' and 'pipeline delete' commands that were altered in #2856, as well as with the 'catalog create' command that was modified in #2884.

Checklist

• Opened this PR as a 'Draft Pull Request' if it is work-in-progress
• Assigned myself to the PR
• Added tests to cover my changes

[merelcht]

The changes look good to me! 👍

[deepyaman]

LGTM!