ci: Ensure that eslint runs on all frontend code (no-changelog) (#4602)

* ensure that eslint runs on all frontend code

* remove tslint from `design-system`

* enable prettier and eslint-prettier for `design-system`

* Delete tslint.json

* use a single editorconfig for the repo

* enable prettier for all code in `design-system`

* more linting fixes on design-system

* ignore coverage for git and prettier

* lintfix on editor-ui

.editorconfig

@@ -15,3 +15,6 @@ indent_size = 2
 [*.yml]
 indent_style = space
 indent_size = 2
+
+[*.ts]
+quote_type = single