Use global styles for filter dropdowns

app/assets/stylesheets/framework/dropdowns.scss

@@ -146,11 +146,16 @@
 @mixin dropdown-item-hover {
   background-color: $dropdown-item-hover-bg;
   color: $gl-text-color;
+  outline: 0;
 
   // make sure the text color is not overriden
   &.text-danger {
     color: $brand-danger;
   }
+
+  .avatar {
+    border-color: $white-light;
+  }
 }
 
 @mixin dropdown-link {

app/assets/stylesheets/framework/filters.scss

@@ -50,8 +50,6 @@
 }
 
 .filtered-search-wrapper {
-  @include new-style-dropdown;
-
   display: -webkit-flex;
   display: flex;
 
@@ -165,16 +163,6 @@
   }
 }
 
-.droplab-dropdown li.filtered-search-token {
-  padding: 0;
-
-  &:hover,
-  &:focus {
-    background-color: inherit;
-    color: inherit;
-  }
-}
-
 .filtered-search-term {
   .name {
     background-color: inherit;
@@ -336,21 +324,12 @@
 
 .filtered-search-history-dropdown-content {
   max-height: none;
-}
 
-.filtered-search-history-dropdown-item,
-.filtered-search-history-clear-button {
-  @include dropdown-link;
-
-  overflow: hidden;
-  width: 100%;
-  margin: 0.5em 0;
-
-  background-color: transparent;
-  border: 0;
-  text-align: left;
-  white-space: nowrap;
-  text-overflow: ellipsis;
+  .filtered-search-history-dropdown-item,
+  .filtered-search-history-clear-button {
+    white-space: nowrap;
+    text-overflow: ellipsis;
+  }
 }
 
 .filtered-search-history-dropdown-token {
@@ -402,24 +381,9 @@
   }
 }
 
-%filter-dropdown-item-btn-hover {
-  text-decoration: none;
-  outline: 0;
-
-  .avatar {
-    border-color: $white-light;
-  }
-}
-
 .droplab-dropdown .dropdown-menu .filter-dropdown-item {
   .btn {
-    border: 0;
-    width: 100%;
-    text-align: left;
-    padding: 8px 16px;
     text-overflow: ellipsis;
-    overflow: hidden;
-    border-radius: 0;
 
     .fa {
       width: 15px;
@@ -434,11 +398,6 @@
       height: 17px;
       top: 0;
     }
-
-    &:hover,
-    &:focus {
-      @extend %filter-dropdown-item-btn-hover;
-    }
   }
 
   .dropdown-light-content {
@@ -459,17 +418,9 @@
       word-break: break-all;
     }
   }
-
-  &.droplab-item-active .btn {
-    @extend %filter-dropdown-item-btn-hover;
-  }
 }
 
 .filter-dropdown-loading {
   padding: 8px 16px;
   text-align: center;
 }
-
-.issues-details-filters {
-  @include new-style-dropdown;
-}