MDL-63988 core_my: add course shortname to dashboard blocks …

* all dashboard card templates moved to /course/templates/
* added aria labels for course short name
* removed ":" from other course aria strings to improve screenreader output

theme/bootstrapbase/less/moodle/blocks.less

@@ -287,6 +287,9 @@
         border: 1px solid @tableBorder;
         .border-radius(@baseBorderRadius);
     }
+    .multiline {
+        white-space: normal;
+    }
     .summary img {
         max-width: 100%;
     }