Move random elements to policyengine-uk-data

[MaxGhenis]

As we have done in the US for stability and keeping the rules engine deterministic. Includes benefit take-up, private school attendance, and so on.

[nikhilwoodruff]

I think this is causing a bug where take up is varying before and after the consumer-incident taxes, so I'll work on this now.

[nikhilwoodruff]

Fixed in terms of the actual data package having the take up values. But the logic is still in PE-UK, so leaving open- we should move it to the data package.