Resolve #3448470 "Gitlabci fix eslint"
https://www.drupal.org/project/field_group/issues/3448470
Fixed ESLint errors on GitlabCI:
- Fixed all validation errors such as unnamed functions, variable names, indentations, etc...
- Added file
.eslintignore
to ignore deprecateddrupalci.yml
configuration file. - GitlabCI build: Required ESLint tests to pass.
- Ignored certain lines of code which would need to be refactored to vanilla JS (
jquery/no-
rules).