all_channels: Restrict channel name to one line

Previously, long name could span multiple lines when the system font
size was large, causing the row height to become insconsistent with
other items. Limiting the name to a single line ensures consistent
row height, similar to how it's done on the Channel Page.

Fixes #1914

Author: chungwwei

lib/widgets/all_channels.dart

@@ -112,6 +112,8 @@ class AllChannelsListEntry extends StatelessWidget {
               iconDataForStream(channel)),
             Expanded(
               child: Text(
+                maxLines: 1,
+                overflow: TextOverflow.ellipsis,
                 style: TextStyle(
                   color: designVariables.textMessage,
                   fontSize: 17,