views: Append topic links in message info view.

This is a summing up commit that appends topic links in message info
view (if present).

Fixes #709.

zulipterminal/ui_tools/views.py

@@ -1242,6 +1242,8 @@ def __init__(self, controller: Any, msg: Message, title: str,
                 ('Edit History', f"Press {keys} to view")
             )
         # Render the category using the existing table methods if links exist.
+        if topic_links:
+            msg_info.append(('Topic Links', []))
         if message_links:
             msg_info.append(('Message Links', []))
         if time_mentions:
@@ -1267,7 +1269,18 @@ def __init__(self, controller: Any, msg: Message, title: str,
         #               + 1 '<Any> Links' category label.
         slice_index = len(msg_info[0][1]) + 2
 
+        if topic_links:
+            topic_link_widgets, topic_link_width = (
+                self.create_link_buttons(controller, topic_links)
+            )
+
+            widgets = (widgets[:slice_index] + topic_link_widgets
+                       + widgets[slice_index:])
+            popup_width = max(popup_width, topic_link_width)
+
         if message_links:
+            if topic_links:
+                slice_index += (len(topic_links) + 2)
             message_link_widgets, message_link_width = (
                 self.create_link_buttons(controller, message_links)
             )
@@ -1288,7 +1301,10 @@ def create_link_buttons(
 
         for index, link in enumerate(links):
             text, link_index, _ = links[link]
-            caption = f"{link_index}: {text}\n{link}"
+            if text:
+                caption = f"{link_index}: {text}\n{link}"
+            else:
+                caption = f"{link_index}: {link}"
             link_width = max(
                 link_width,
                 len(max(caption.split('\n'), key=len))