test-validator: Add --max-compute-units flag (#24130)

* test-validator: Add `--max-compute-units` flag

* Add `RuntimeConfig` for tweaking runtime behavior

* Actually add the file

* Move RuntimeConfig to runtime

runtime/src/lib.rs

@@ -44,6 +44,7 @@ mod pubkey_bins;
 mod read_only_accounts_cache;
 pub mod rent_collector;
 mod rolling_bit_field;
+pub mod runtime_config;
 pub mod secondary_index;
 pub mod serde_snapshot;
 mod shared_buffer_reader;