Feat: add entries for JH about repo blob viewers

Changelog: added
MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/143019

app/assets/javascripts/repository/components/blob_viewers/index.js

 export const viewers = {
   csv: () => import('./csv_viewer.vue'),
-  download: () => import('./download_viewer.vue'),
+  download: () => import('jh_else_ce/repository/components/blob_viewers/download_viewer.vue'),
   image: () => import('./image_viewer.vue'),
   video: () => import('./video_viewer.vue'),
   empty: () => import('./empty_viewer.vue'),
   text: () => import('~/vue_shared/components/source_viewer/source_viewer.vue'),
-  pdf: () => import('./pdf_viewer.vue'),
-  lfs: () => import('./lfs_viewer.vue'),
+  pdf: () => import('jh_else_ce/repository/components/blob_viewers/pdf_viewer.vue'),
+  lfs: () => import('jh_else_ce/repository/components/blob_viewers/lfs_viewer.vue'),
   audio: () => import('./audio_viewer.vue'),
   svg: () => import('./image_viewer.vue'),
   sketch: () => import('./sketch_viewer.vue'),