Fix prediction-markets tests, I

[maltekliemann]

What does it do?

• Tests admin_move_market_to_resolved with disputed markets.
• Removes test it_resolves_a_disputed_market involving simple_disputes.
• Moves it_resolves_a_disputed_court_market to integration tests.
• Uses more granular origins for testing.
• Fixes wrong use of origins in benchmarks.
• Adds missing tests for buy_complete_set.
• Adds missing tests for create_market.

What important points should reviewers know?

Is there something left for follow-up PRs?

Remove all other TODOs. Doing that in separate PRs to avoid bloating this one.

What alternative implementations were considered?

Are there relevant PRs or issues?

References