vue-i18n: Add ESLint rules to detect vue i18n offences

Part of https://gitlab.com/gitlab-org/manage/issues/20

• Add vue bare string and vue bare attribute eslint-rules to enforce checking for i18n offences
• Enable eslint-plugin-i18n for .vue files
• Disable false positives caused by eslint-plugin-i18n
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/8e476a85bf27abdf055e3cb64a647dfd5f1e3d08/app/assets/javascripts/badges/components/badge.vue#L6
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/725d693a1c61d45819ca360b8fda4b686328e7b4/app/assets/javascripts/diffs/components/commit_item.vue#L51
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/18254d75df0676cbb67d50bf9844f03bc9042bcc/app/assets/javascripts/environments/components/environment_item.vue#L298
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/e438b1b9d0860458061733433a16c23ef4cd7da8/app/assets/javascripts/repository/components/table/row.vue#L113
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/e438b1b9d0860458061733433a16c23ef4cd7da8/app/assets/javascripts/error_tracking_settings/components/error_tracking_form.vue#L39
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/aa7fd7f1810f1574ad2ade819dacd6d42b87899c/app/assets/javascripts/ide/components/commit_sidebar/list_item.vue#L48
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/407af583e06c3fe56649f0ab47bbeb988ca1270a/app/assets/javascripts/sidebar/components/assignees/assignees.vue#L6
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/e0f0ce1771be73e2cf1a9405b8973d405c7e5501/app/assets/javascripts/vue_merge_request_widget/components/states/mr_widget_merged.vue#L87
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/e0f0ce1771be73e2cf1a9405b8973d405c7e5501/app/assets/javascripts/vue_merge_request_widget/mr_widget_options.vue#L43
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/c1411c8abc9011c006f18bc448d9823366e91dec/app/assets/javascripts/vue_shared/components/changed_file_icon.vue#L49
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/c1411c8abc9011c006f18bc448d9823366e91dec/app/assets/javascripts/vue_shared/components/deprecated_modal.vue#L42
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/c1411c8abc9011c006f18bc448d9823366e91dec/app/assets/javascripts/vue_shared/components/markdown/header.vue#L40
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/c1411c8abc9011c006f18bc448d9823366e91dec/app/assets/javascripts/vue_shared/components/select2_select.vue#L6
  • https://gitlab.com/gitlab-org/gitlab-ce/blob/c1411c8abc9011c006f18bc448d9823366e91dec/app/assets/javascripts/vue_shared/components/stacked_progress_bar.vue#L81