use edge-mock instead of service-worker-mock

[samuelcolvin]

I propose that you suggest the user of edge-mock (which I've just built) instead of service-worker-mock.

I've made the necessary changes here for the switch.

A few advantages of edge-mock:

1. service-workers the project which service-worker-mock is a part of is no longer maintained
2. edge-mock provides support for KV store mocking out-of-the-box
3. edge-mock properly supports ArrayBuffer and ReadableStream which service-worker-mock does not
4. edge-mock has close to 100% test coverage and is written in typescript
5. All the implementations provided by edge-mock are fully compliant with the types they implement in typescript

[samuelcolvin]

I'm not really clear if I should be including changes to package-lock.json, I assume from the number of changes that it's somehow very outdated.

[stevenroussey-privicy]

Nice! Might update the edge-mock version here.