* Introduce Echo for collecting frontend metrics

* Update public/app/core/services/echo/Echo.ts

Co-Authored-By: Peter Holmberg <peterholmberg@users.noreply.github.com>

* Custom meta when adding event

* Rename consumer to backend

* Remove buffer from Echo

* Minor tweaks

* Update package.json

* Update public/app/app.ts

* Update public/app/app.ts

* Collect paint metrics when collecting tti. Remove echoBackendFactory

* Update yarn.lock

* Move Echo interfaces to runtime

* progress on meta and echo

* Collect meta analytics events

* Move MetaanalyticsBackend to enterprise repo

* Fixed unit tests

* Removed unused type from test

* Fixed issues with chunk loading (reverted index-template changes)

* Restored changes

* Fixed webpack prod