Performance fixes + IndexedDb Replacement

[pkarw]

Related issues

#2021, #2107

Short description and why it's useful

@NataliaTepluhina please update the docs + Upgrade notes please:

Starting from Vue Storefront 1.7 we've changed the Caching strategy + Offline ready features:

• by default, the ElasticSearch Queries are executed using GET method - and therefore are cached by Service Worker (c - set it to POST for the previous behavior and if You're using graphql),
• by default products and queries cache is set in the LocalStorage with a quota set to 4MB (config.server.elasticCacheQuota). If the storage quota is set, the cache purging is executed each 30s using LRU algorithm. Local Storage is limited to 5MB in most browsers
• we've added config.server. disableLocalStorageQueriesCache which is set to true by default. When this option is on then we're not storing the ElasticSearch results in local cache - this is due to the fact that results are by default cached in Service Worker cache anyway.

Backward compatibility - to reverse to the 1.0-1.6 behavior please set:

• set config.server. disableLocalStorageQueriesCache = false,
• set config.elasticsearch.queryMethod = POST
• set config.localForage.defaultDrivers.elasticCache = INDEXEDDB

@patzick seems like this also closes #2021 :) Sorry! :)

Screenshots of visual changes before/after (if there are any)

(if you made any changes in the UI layer please provide before/after screenshots)

Screenshot of passed e2e tests (if you are using our standard setup as a backend)

(run yarn test:e2e and paste the results. If you are not using our standard backend setup or demo.vuestorefront.io you can ommit this step)

Upgrade Notes and Changelog

• No upgrade steps required (100% backward compatibility)
• I've updated the Upgrade notes and Changelog on how to port existing VS sites with this new feature

Contribution and currently important rules acceptance

• I read and followed contribution rules
• I read the TypeScript Action Plan and adjusted my PR according to it
• I read about Vue Storefront Modules and I am aware that every new feature should be a module