Fix calendar unit test

fix_6829 [ci skip]

Data selector multi step refactor + replace field mapping with data selector

A way to check backend i18n

Fix data loading and loading state

Persist default axes of a visualization [WIP]

Reduce number of Jest test runner worker threads

This commit reduces the number of test runner workers for Jest tests
from 10 to 8. This will use less memory and hopefully avoid Circle CI
4GB memory limit test failures. It also fixes some tests that have
nested `it` clauses. This doesn't run correctly on older versions of
Jest and will fail fast on newer versions of Jest.

Fixes #6790

Add i18n debug feature to assist in finding untranslated strings

Fixup expression name issues on MySQL [ci drivers]

Fix broken getting-started url.

Fixup delete database dialog

Ensure aggregation expressions have base_type included

HTML markup isn't supported inside an internationalized string