Calling Store.clear() (sometimes) corrupts the Pepr Store

[btlghrants]

Running all e2e tests for the hello-pepr-store excellent example will fail intermittently IF the commented out scenarios in store.e2e.test.ts and store.ts are uncommented.

It appears that the call to Store.clear() is somehow "corrupting" the store itself -- often, after calling that method, the Pepr logs will just begin listing repeated 422 (Unprocessable Entity) when trying to update the store... and it never self-corrects.

What's going on with Store.clear()?