Refactor GitHub workflows for better organization and clarity

[dirtyformal]

This PR replaces previous workflows with four new workflows:

• build_boundaries_only.yml: Manually compiles boundary files using Node.js and uploads the result as an artifact. It checks out the code, sets up Node.js, runs a compile script, and uploads TRACONBoundaries.geojson.
• enforce_dir_structure.yml: Ensures that the repository's directory structure is correct. It runs on pushes to the main branch, pull requests, and manual triggers.
• json_validate.yml: Validates JSON and YAML files on pushes, pull requests, and manual triggers. It checks out the code, runs the GrantBirki/json-yaml-validate action, and posts comments on pull requests with validation results.
• release.yml: Manually compiles a boundary file, tags a new version, generates a changelog, and creates a GitHub release. It uploads the compiled file (TRACONBoundaries.geojson) as a release asset.

Motivation and Context

Simplifies the build process.

How to prove the effect of this PR?

Tested in a private repository with a copy of the current dataset.

Additional info

This PR also requires amendment of the dataset due to an existing error. SUMU.json sits in the /Boundaries/ dir, and not in its own discrete folder. This should be done before merging this PR.

Is this a breaking change?

• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• My change or addition follow the formatting standard of the project.
• I am on the list of approved contributors.