* move test_helpers to the core
* create base tsconfig
* all tsconfigs use the base one
* use test_helpers exposed from the src/core
* move getFieldFormatsRegistry to data plugin
* add test_utils project
* compile types after checkout
* add a stub for platform tsconfig.json
* fix broken import
* fix broken path to the base config
* set tsBuildInfoFile for project without outDir
* do not commit tsbuildinfo file
* do not check output d.ts files
* fix type error
* use separate config to build types
* rollback changes to include paths
* mute import zone error
* rename files to avoid references to tsd
* do not use tsd for type tests
* include all ts files in project
* run buildRefs before type check to ensure the latest version
* store tsbuildinfo locally
* update paths to base config
* comment out core/tsconfig.json
* remove ui path
* fix wrong tsbuildinfo path
* update build scripts to not set inline source-maps for code coverage run
* [ftr] browser console log processing cleanup
* get last coverage piece directly via webdriver
* more cleanup
* review feedback
Since this is being imported by the UI as a package, we need to transpile for the
browsers we need to support.
Fixes#42782
Signed-off-by: Tyler Smalley <tyler.smalley@elastic.co>