Add tag category to display as text in the UI

Let's:
- Implement the colour coding in the UI
- Remove the textual display of tag category after implementing colours
- Ensure that all the person displays are updated after every cattag command

src/main/java/seedu/address/ui/PersonCard.java

@@ -51,7 +51,9 @@ public PersonCard(Person person, int displayedIndex) {
         email.setText(person.getEmail().value);
         person.getTags().stream()
                 .sorted(Comparator.comparing(tag -> tag.tagName))
-                .forEach(tag -> tags.getChildren().add(new Label(tag.tagName)));
+                // Tag category displayed for visual testing
+                // TODO: remove tag category text display after implementing colour code
+                .forEach(tag -> tags.getChildren().add(new Label(tag.tagName + " " + tag.getTagCategory())));
 
         // add horizontal and vertical gaps for the tags FlowPane
         tags.setHgap(5);

src/main/java/seedu/address/ui/TagCard.java

@@ -26,6 +26,8 @@ public class TagCard extends UiPart<Region> {
     public TagCard(Tag tag, int displayedIndex) {
         super(FXML);
         this.tag = tag;
-        tagName.setText((displayedIndex + 1) + ". " + tag.tagName);
+        // Tag category displayed for visual testing
+        // TODO: remove tag category text display after implementing colour code
+        tagName.setText((displayedIndex + 1) + ". " + tag.tagName + "(" + tag.getTagCategory() + ")");
     }
 }