Consolidate user avatar Vue logic

Creates 3 vue components:

1. user-avatar-link
2. user-avatar-image
3. user-avatar-svg

and implements them in several places.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/31017

• Port to EE
• Test each implementation manually

EE Compatible Branch: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1699

config/webpack.config.js

@@ -87,7+87,7 @@
       {
         test: /\.svg$/,
         loader: 'raw-loader',
       },
       {
         test: /\.(gif|png)$/,
         loader: 'url-loader',
@@ -186,7+186,7 @@
       'emojis':         path.join(ROOT_PATH, 'fixtures/emojis'),
       'empty_states':   path.join(ROOT_PATH, 'app/views/shared/empty_states'),
       'icons':          path.join(ROOT_PATH, 'app/views/shared/icons'),
-      'images':          path.join(ROOT_PATH, 'app/assets/images'),
+      'images':         path.join(ROOT_PATH, 'app/assets/images'),
       'vendor':         path.join(ROOT_PATH, 'vendor/assets/javascripts'),
       'vue$':           'vue/dist/vue.esm.js',
     }