[pacostas]

Summary

This PR is a follow up PR of the #1454

More specifically, the setup.sh script, uses code that has the same functionality, as we already have for the rest of the buildpacks under the script repository. This PR, refactors the setup.sh script and applies the same structure under the actions/tools/setup action. This is useful, as having the same codebase structure accros implementations, is easier for the authors to understand and also, in case a change in one of the script has been made e.g. to fix a bug, is easier to apply to the rest of the scripts too, as they are exactly the same, which increases the maintenance of all the scripts in general.

Use Cases

Checklist

• I have viewed, signed, and submitted the Contributor License Agreement.
• I have linked issue(s) that this PR should close using keywords or the Github UI (See docs)
• I have added an integration test, if necessary.
• I have reviewed the styleguide for guidance on my code quality.
• I'm happy with the commit history on this PR (I have rebased/squashed as needed).