[IMP] web_kanban: use flex for progress bar instead of hard-coded width

addons/hr_recruitment/static/src/less/hr_recruitment_dashboard.less

@@ -2,16 +2,5 @@
 	.o_kanban_record {
 		max-width: 500px;
 		min-width: 450px;
-
-		.o_progressbar_title {
-			width: 25%;
-		}
-		.o_progress {
-			width: 60%;
-		}
-		.o_progressbar_value {
-			width: 15%;
-		}
-
 	}
 }

addons/mass_mailing/static/src/less/mass_mailing.less

@@ -1,14 +1,5 @@
 .o_kanban_view {
     .oe_kanban_mass_mailing {
-        .o_progressbar .o_progressbar_title {
-            width: 25%;
-        }
-        .o_progressbar .o_progress {
-            width: 50%;
-        }
-        .o_progressbar .o_progressbar_value {
-            width: 25%;
-        }
         .o_title {
             margin-bottom: 16px;
         }

addons/web_kanban/static/src/less/kanban_view.less

@@ -300,15 +300,19 @@
             }
         }
         .o_progressbar {
+
+            .o-flex-display();
+
             .o_progressbar_title {
-                width: 20%;
+                .o-flex(0, 0, auto);
             }
             .o_progress {
-                width: 60%;
-                height: 15px;
+                margin-top: 3px;
+                .o-flex(1, 1, auto);
             }
             .o_progressbar_value {
-                width: 20%;
+                .o-flex(0, 0, auto);
+                width: auto;
                 text-align: right;
             }
         }