Unhide the view source event toggle - it works well enough (#11336)

Author: t3chguy

res/css/views/rooms/_EventTile.pcss

@@ -1203,11 +1203,6 @@ $left-gutter: 64px;
                 height: 14px; /* avatar img size */
             }
 
-            .mx_ViewSourceEvent_toggle {
-                display: none; /* hide the hidden event expand button, not enough
-                space, view source can still be used */
-            }
-
             &.mx_EventTile_selected .mx_EventTile_line,
             .mx_EventTile_line {
                 $line-height: $font-12px;