add tpc-ds tests and property-based testing utilities

This change introduces a new `property_based.rs` test utility which lets us evaluate
correctness using properties. These are useful for evaluating correctness when
we do not know the expected output of a test (ex. if we were to fuzz the database
with randomized data or randomzed queries, then we can only verify the output using
properties).

This change does not introduce fuzzing, but it introduces a TPC-DS test. This test
randomly generates data using the duckdb CLI and runs 99 queries on a distributed cluster.
The query outputs are validated against single-node datafusion using test utils in
`metamorphic.rs`. This test also randomizes the test cluster parameters - there's no harm
in doing so.

Next steps:
- Add ordering oracle to validate ORDER BY correctness
  - Idea: Inspect the ordering properties in the logical plan and assert this
    property on the `RecordBatch`es
- Add fuzzing
  - Now that we have property-based testing utils, we can properly fuzz the project
    using SQLancer
  - SQLancer produces INSERT and SELECT statements which we could point at a datafusion
    distributed cluster and verify against single node datafusion
  - Although it doesn't support nested select statements, 70% of the queries were valid
    datafusion queries, meaning these are good test cases for us
- Add metrics oracle to validate output_rows metric / metrics propagation

Author: jayshrivastava

.gitignore

@@ -1,4 +1,5 @@
 /.idea
 /target
 /benchmarks/data/
-testdata/tpch/data/
+testdata/tpch/data/
+testdata/tpcds/data/