feature: Updated the text when a learner earns a cert on the Dashboard

[MICROBA-678]

This patch will update the text on the course dashboard when a learner
successfully earns a certificate and that certificate is available. It
also adds to the Outline API for the Outline in the Learning MFE so that
the same changes can be made there.

lms/static/sass/multicourse/_dashboard.scss

@@ -956,10 +956,6 @@
         margin: 0;
       }
 
-      &.course-status-processing {
-        color: #0d7d4d;
-      }
-
       .credit-action {
         .credit-btn {
           @extend %btn-pl-yellow-base;
@@ -1071,6 +1067,11 @@
         }
       }
 
+      &.course-status-earned-not-available,
+      &.course-status-certavailable {
+        color: #0d7d4d;
+      }
+
       &.course-status-certavailable {
         .message-copy {
           width: flex-grid(6, 12);