Improve label and text wrapping (#14113)

* Improve label wrapping

- Adjust issue list styles so labels can wrap on the same line as the
  text. This relies on `display: inline` with the HTML whitespace being
  used as the separator.
- Add global word-break: break-word. This should generally avoid text
  overflows in various places.

* add whitespace to history labels

* use overflow-wrap

* restore word-break rules

* use correct pre

* use better selector for middle align

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

web_src/less/shared/issuelist.less

@@ -29,6 +29,10 @@
       font-size: 16px;
       min-width: 0;
       font-weight: 600;
+
+      > * {
+        vertical-align: middle;
+      }
     }
 
     .issue-item-bottom-row {