Introduce scripts for common tasks

[alejandrosame]

What?

We need to align all files that make similar setup and testing tasks.

Why?

Currently, we make similar tasks in different environments. For example, we have repeated code for setup https://github.com/OpenMined/PyDP/blob/dev/Dockerfile#L36, https://github.com/OpenMined/PyDP/blob/dev/.github/workflows/pypipublish_osx.yml#L18, https://github.com/OpenMined/PyDP/blob/dev/prereqs_linux.sh#L58, etc. This makes updates messy because we have to go and chase different files to align repeated code.

Breakdown

• Create a folder scripts to hold all utility scripts used across the repository.

• Update Makefile to make use of scripts.

• Update github workflows to make use of scripts.

  • build_dev_docs.yml
  • pypipublish_linux.yml
  • pypipublish_osx.yml
  • pypipublish_windows.yml
  • style_check.yml
  • tests.yml

• Update Dockerfile to make use of scripts

• Update prereqs_linux.sh to make use of scripts

• Update prereqs_mac.sh to make use of scripts

• Update contribution guidelines to point to the existence of the folder and require reusing/creating scripts when appropriate.

Additional Context

Add any other context about the problem here.