Remove illustration size in empty state component

Problem

Empty state component added svg-250 class that limits the illustration size in !106 (diffs) which could lead to misdirection like in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/9650#note_143596387. See discussion in !106 (comment 120725601).

Proposal

Let's remove the svg-250 class for now and restore the default empty state illustration size.

Investigate further improvements for empty state illustrations like live area, bounding box, etc. See also relevant discussion for icons in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20748#note_99714456, https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20748#note_100173583, and https://gitlab.com/gitlab-org/design.gitlab.com/issues/113.

Possible fix

diff --git a/components/regions/empty_state/empty_state.vue b/components/regions/empty_state/empty_state.vue
index 274ae75..bb4234f 100644
--- a/components/regions/empty_state/empty_state.vue
+++ b/components/regions/empty_state/empty_state.vue
@@ -89,7 +89,7 @@ export default {
     <div class="col-12">
       <div
         v-if="svgPath"
-        class="svg-content svg-250"
+        class="svg-content"
       >
         <img
           :src="svgPath"