Problem:
sim was generating compound selects like this:
- pick a random `table`
- create a random single SELECT
- create `n` random compound SELECTs (UNION ALL etc)
assign a WHERE clause that always has a condition based on `table`
This can result in e.g.
```
SELECT a FROM foo WHERE bar.x = 'baz'
```
Solution:
Don't base the WHERE clause on a table that might not be referenced
in the query.
Again, the only reason this wasn't caught before was because `FaultyQuery`
and `FsyncNoWait` are the only paths where this is actually tested with an
assertion, and those are both disabled
* Without tracing crate we cannot log anything that happens in
limbo_core
* IO never ran in step loop inside simulator.
* Added update queries (which currently loop forever for some reason I'm
debugging).
- previous query generation method was faulty, producing wrong assertions
- this commit adds a new arbitrary_from implementation for predicates
- new implementation takes a table and a row, and produces a predicate that would evaluate to true for the row
this commit makes small changes to the main for increasing readability
better counterexample minimization.
- it separates interaction plans from their state of execution
- it removes closures from the property definitions, encoding properties as an enum variant, and deriving the closures from the variants.
- it adds some naive counterexample minimization capabilities to the Limbo simulator and reduces the plan sizes considerably.
- it makes small changes to various points of the simulator for better error reporting, enhancing code readability, small fixes to handle previously missed cases
