Issue #3455082: Fully implement, adjust and review the...

Issue #3455082: Fully implement, adjust and review the "commerce-product-availability-product-availability-default" twig template

Closes #3455082

css/availability_indicator.css

-.product-availability-indicator.product-availability-indicator--green {
+.stock-status__availability-status-icon--available {
   color: green;
 }
-.product-availability-indicator.product-availability-indicator--yellow {
+.stock-status__availability-status-icon--limited-availability {
   color: yellow;
 }
-.product-availability-indicator.product-availability-indicator--red {
+.stock-status__availability-status-icon--unavailable {
   color: red;
 }