Make search input smaller on medium width screens

Give more space to search results.

src/main/webapp/app/mock-search/mock-search.component.html

@@ -5,10 +5,10 @@
      (scrolled)="onScroll()">
 
     <jhi-search-input
-        class="col-12 col-md-6 col-lg-4 col-xl-3"
+        class="col-12 col-md-5 col-lg-4 col-xl-3"
         (searchInputEvent)="updateSearchInput($event)">
     </jhi-search-input>
-    <div class="col-12 col-md-6 col-lg-8 col-xl-9">
+    <div class="col-12 col-md-7 col-lg-8 col-xl-9">
         <div class="row">
             <jhi-exercise-card *ngFor="let result of results"
                                class="card-container col-12 col-lg-6 col-xl-4"