Merge pull request #6276 from IgniteUI/fix-for-#6270

fix(dropdown): Removing shadow only for --select mod

Author: rkaraivanov

projects/igniteui-angular/src/lib/core/styles/components/drop-down/_drop-down-theme.scss

@@ -225,6 +225,7 @@
     %igx-drop-down__list {
         overflow-y: auto;
         background: --var($theme, 'background-color');
+        box-shadow: --var($theme, 'shadow');
         min-width: rem(128px);
 
         &:empty {
@@ -236,6 +237,10 @@
         }
     }
 
+    %igx-drop-down__list--select {
+        box-shadow: none;
+    }
+
     %igx-drop-down__header,
     %igx-drop-down__item {
         display: flex;
@@ -251,10 +256,6 @@
         cursor: pointer;
         padding: map-get($item-padding, 'comfortable');
 
-        //&%igx-drop-down__list--select {
-        //    max-width: calc(100% + #{$item-padding-comfortable} * 2);
-        //}
-
         &:focus {
             outline: 0;
             outline-color: transparent;
@@ -271,19 +272,11 @@
     %igx-drop-down__item--cosy {
         height: map-get($item-height, 'cosy');
         padding: map-get($item-padding, 'cosy');
-        //
-        //&%igx-drop-down__list--select {
-        //    max-width: calc(100% + #{$item-padding-cosy} * 2);
-        //}
     }
 
     %igx-drop-down__item--compact {
         height: map-get($item-height, 'compact');
         padding: map-get($item-padding, 'compact');
-        //
-        //&%igx-drop-down__list--select {
-        //    max-width: calc(100% + #{$item-padding-compact} * 2);
-        //}
     }
 
     %igx-drop-down__header {