Feat: command for installing specific Python runtime

[mt-kelvintaywl]

Describe Request:

I am hoping if it is possible to extend this Orb to include a install command, much like the Node Orb's.

In our use case, we have a job running on a non-Python executor (e.g., Ruby related). Since multiple executors for supporting multiple language runtime environments are not feasible, I end up having to specifically install a Python runtime in a job's step. If there was something like what the Node Orb's install command offers, this would have been great (one-liner or so for me!)

Examples:

# job
my_custom_job:
    docker:
      - image: circleci/ruby:2.7.2
    steps:
      - checkout
+     - python/install:
+         python-version: '3.8.7'
      - run:
          command: |
            which python3.8