Limit the number of Elastic queries in the vue-storefront-api per each catalog request

What is the motivation for adding / enhancing this feature?

Currently, per each catalog request, we're executing at least 2 Elastic queries:

The rates can be stored in Redis/local memory as they're changing extremely rarely!

Where to start:

Related to: vuestorefront/vue-storefront#3367

[ ] tax rates are being stored in the local cache and each api/catalog request engages Elastic just for single query

Pick one option.

[x] This is a normal feature request. This should be available on https://test.storefrontcloud.io and then after tests this can be added to next Vue Storefront version. In this case Developer should create branch from develop branch and create Pull Request 2. Feature / Improvement back to develop.
[ ] (Pick this option only if you're sure) This is an important improvement request for current Release Candidate version on https://next.storefrontcloud.io and should be placed in next RC version. In this case Developer should create branch from release branch and create Pull Request 3. Stabilisation fix back to release.
[ ] (Pick this option only if you're sure) This is a critical improvement request for current Stable version on https://demo.storefrontcloud.io and should be placed in next stable version. In this case Developer should create branch from hotfix or master branch and create Pull Request 4. Hotfix back to hotfix.