fix 2714 & 3817 line length problems

* Fixes: owid#2714 long line length - note that I think these will still wrap as the only change is the date nowrap addition.
* This will be why I opted for `vw` unit to minimise the long line outcome.
* The same line fixes the problem Lucas was having: wrapping dates.

packages/@ourworldindata/grapher/src/tooltip/Tooltip.scss

@@ -227,6 +227,7 @@
             }
 
             td.time-notice {
+                white-space: nowrap;
                 font-weight: $medium;
                 text-indent: 20px;
                 text-align: right;