fix(forms): add validation icons for <select>s and fix its position…

… for `<textarea>` (#1371)

* Reset to Bootstrap default for feedback icon on select
* Setting the icon in the top right corner instead of center right

Co-authored-by: Julien Déramond <julien.deramond@orange.com>

scss/_variables.scss

@@ -1117,7 +1117,9 @@ $form-select-bg-size:               .875rem 1rem !default; // In pixels because
 $form-select-indicator:             url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 14 7'><path d='M7 7 0 0h14L7 7z'/></svg>") !default;
 $form-select-disabled-indicator:    url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 14 7'><path fill='#{$form-select-disabled-color}' d='M7 7 0 0h14L7 7z'/></svg>") !default; // Boosted mod
 
-// Boosted mod: no icon for validated select
+$form-select-feedback-icon-padding-end: $form-select-padding-x * 2.5 + $form-select-indicator-padding !default;
+$form-select-feedback-icon-position:    center right $form-select-indicator-padding !default;
+$form-select-feedback-icon-size:        $input-height-inner-half $input-height-inner-half !default;
 
 $form-select-border-width:        $input-border-width !default;
 $form-select-border-color:        $input-border-color !default;

scss/mixins/_forms.scss

@@ -29,10 +29,22 @@
         @include form-validation-state-selector($state) {
           background-image: escape-svg($icon);
           background-repeat: no-repeat;
-          background-position: right $input-height-inner-quarter center;
+          background-position: right $input-height-inner-quarter top subtract($input-height-inner-quarter, 2px);
           background-size: $input-height-inner-half $input-height-inner-half;
         }
       }
+
+      .form-select {
+        @include form-validation-state-selector($state) {
+          &:not([multiple]):not([size]),
+          &:not([multiple])[size="1"] {
+            padding-right: $form-select-feedback-icon-padding-end;
+            background-image: escape-svg($form-select-indicator), escape-svg($icon);
+            background-position: $form-select-bg-position, $form-select-feedback-icon-position;
+            background-size: $form-select-bg-size, $form-select-feedback-icon-size;
+          }
+        }
+      }
     }
   } @else {
     .#{$state}-feedback {