Tag Python Core with Python Standards

[lizTheDeveloper]

Issue this as a PR to the standards branch. Use the python-standards branch as the main working branch.

• [x] Re-bucket workouts in https://github.com/enkidevs/curriculum/tree/master/python/core
• [ ] Re-bucket workouts in https://github.com/enkidevs/curriculum/tree/master/python/data-structures
• [ ] Merge Core and Data Structures
• [ ] Tag Core with Standards and Objectives for Python https://github.com/sagelabs/standards/tree/master/python

Format:

standards:
  sql.aggregate-single-table: 10

For points, just use 10 for now, we'll dynamically allocate points for real later.