[IMP] web: properly display min and max abs when less that 3 abs.

In graph line mode, min and max abs are
displayed beyond the screen when there are less
than 3 abs.
This is happening because nvd3 fixes their
text-anchor to 'middle'. The present commit fixes
correctly their text-anchors to start and end
respectively by using the '!important' rule (it
seems difficult to do otherwise).

Co-authored-by: Mohammed Shekha <msh@openerp.com>

Related to Task: 1917958

addons/web/static/src/js/views/graph/graph_renderer.js

@@ -451,10 +451,6 @@ return AbstractRenderer.extend({
         // of the tiny margins.
         if (ticksLabels.length > 3) {
             $svgContainer.find('svg .nv-x g.nv-axisMaxMin-x > text').hide();
-        } else {
-            // Since the graph is on full container have first and last label in the container
-            $svgContainer.find('svg .nv-x g.nv-axisMin-x > text').css({'text-anchor': 'start'});
-            $svgContainer.find('svg .nv-x g.nv-axisMax-x > text').css({'text-anchor': 'end'});
         }
 
         return chart;

addons/web/static/src/scss/graph_view.scss

@@ -24,6 +24,14 @@
                     // ligther area color
                     fill-opacity: 0.1;
                 }
+                .nv-lineChart .nv-x.nv-axis .nv-axisMaxMin-x {
+                    &.nv-axisMin-x text {
+                        text-anchor: start !important;
+                    }
+                    &.nv-axisMax-x text {
+                        text-anchor: end !important;
+                    }
+                }
             }
         }
     }