Reworks workflows into script (#661)

* Reworks some workflows to run a script instead

Advantages are:
- Only one set of tests needs maintenance.
- Local results match workflows, no surprises.
- Reduced reliance on GitHub actions.

Fixes #50, #168, #169, #171, #507

* Adds macos to the test matrix

libraries/persistent_store/fuzz/examples/store.rs

@@ -13,8 +13,7 @@
 // limitations under the License.
 
 use fuzz_store::{fuzz, StatKey, Stats};
-use std::io::Write;
-use std::io::{stdout, Read};
+use std::io::{stdout, Read, Write};
 use std::path::Path;
 
 fn usage(program: &str) {