Add stock ticker dataset

[ghanse]

Proposed changes

Added the following standard datasets:

basic/stock_ticker - Simulates daily stock ticker data with open, close, high, low, and volume
multi_table/sales_order - Simulates sales orders, line items, shipments, invoices, customers, carriers, and catalog items

Types of changes

What types of changes does your code introduce to dbldatagen?
Put an x in the boxes that apply

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Change to tutorials, tests or examples
• Non code change (readme, images or other non-code assets)
• Documentation Update (if none of the other choices apply)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR.
If you're unsure about any of them, don't hesitate to ask. We're here to help!
This is simply a reminder of what we are going to look for before merging your code.

• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in downstream modules
• Submission does not reduce code coverage numbers
• Submission does not increase alerts or messages from prospector / lint

Further comments

I followed the multi_table/telephony example for the sales orders dataset. I had to generate base tables for the final orders, line items, invoices, and shipments tables.

[ronanstokes-db]

looks good to me