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

spec/javascripts/vue_shared/components/user_avatar_image_spec.js

@@ -76,33 +76,3 @@ import UserAvatarImage from '~/vue_shared/components/user_avatar/user_avatar_ima
     });
   });
 })();
-
-/**
- * tooltipClass() {
-      return this.tooltipText ? 'has-tooltip' : '';
-    },
-    tooltipContainer() {
-      return this.tooltipText ? 'body' : null;
-    },
-    avatarSizeClass() {
-      return `s${this.size}`;
-    },
-    imgCss() {
-      return `avatar ${this.tooltipClass} ${this.avatarSizeClass} ${this.css}`;
-    },
-
-
-      <img 
-      :class="imgCss" 
-      :src="src" 
-      :width="size" 
-      :height="size" 
-      :alt="alt" 
-      :data-container='tooltipContainer'
-      :data-title='tooltipText'
-      :data-original-title='tooltipText'/>
-  `,
-};
- * 
- * 
- */
\ No newline at end of file