Resolve "Mark commented lines when feedback is hidden"

Closes #160 (closed)

frontend/src/components/submission_notes/SubmissionCorrection.vue

@@ -8,6 +8,7 @@
       <template slot="table-content" id='sub-lines'>
         <tr v-for="(code, lineNo) in submission" :key="`${submissionObj.pk}${lineNo}`" :id="`sub-line-${lineNo}`">
           <submission-line
+            :hint="hasHiddenComment(lineNo)"
             :code="code"
             :line-no="lineNo"
             @toggleEditor="toggleEditorOnLine(lineNo)"
@@ -180,6 +181,14 @@ export default {
         return da.getTime() - db.getTime()
       })
     },
+    hasHiddenComment (lineNo) {
+      const hasOrigComment = this.origFeedback && this.origFeedback[lineNo]
+        && this.origFeedback[lineNo].length > 0
+
+      const hasUpdatedComment = this.updatedFeedback && this.updatedFeedback[lineNo]
+
+      return !this.showFeedback && (hasOrigComment || hasUpdatedComment)
+    },
     init () {
       SubmissionNotes.RESET_STATE()
       SubmissionNotes.SET_SUBMISSION(this.submissionObj)