[FIX] project: increase clickable zone in dashboard

In the kanban project dashboard, the records are displayed with a column
of small 'boxes' on the right.  Those boxes seems clickable and lead to
other actions, such as issues, forecast, timesheet, ...  However, the
actual clickable zone is the tag 'a' inside those boxes.  This leads to
confused users (myself included).

With this commit, the size of the link is increased to the full width of
the box. This is not the perfect fix, since the height is not
necessarily exactly the same as the surrounding box, but it is
significantly easier to click on it in some cases.

addons/project/static/src/less/project_dashboard.less

@@ -90,10 +90,9 @@
         .o_project_kanban_box {
             position: relative;
             text-align: center;
-            padding: 15px 0 15px 0;
+            padding: 0 0 0 0;
             .o-flex(1, 1, auto);
             .o-flex-display();
-            .o-align-items(center);
             .o-flex-flow(column, nowrap);
             .o-justify-content(center);
         }