bug: service-worker cache seems to be broken

[SgtPooki]

No matter how many times I refresh a page, I cannot get cached response HIT to show in the logs. We should probably be using a persistent blockstore instead and this would solve most of our problems.

I believe cache.put(cacheKey, resp) and cache.match(cacheKey) will not work because of the way the browser cache works... but I also think we have a bug in some mutable checks..

also, fetchAndUpdateCache is always passing mutable=true with await storeReponseInCache({ response, isMutable: true, cacheKey, event }) which can cause cache misses because it's always writing to the mutable cache, instead of the immutable cache when protocol=ipfs

cache workflow needs seriously cleaned up