Fix heatmap axis labels

Author: robertoffmoura

plotly/Test_plotlyfig.m

@@ -2671,5 +2671,20 @@ function testHeatmapTitleAnnotation(tc)
             actualStrings = cellfun(@(ann) ann.text, p.layout.annotations);
             tc.verifyNotEmpty(actualStrings(contains(actualStrings, titleString)));
         end
+
+        function testHeatmapAxisLabels(tc)
+            fig = figure("Visible","off");
+            data = [1 2; 3 4];
+            xLabelText = "X Axis Label";
+            yLabelText = "Y Axis Label";
+            heatmap(data);
+            xlabel(xLabelText);
+            ylabel(yLabelText);
+
+            p = plotlyfig(fig,"visible","off");
+
+            tc.verifyEqual(p.layout.xaxis1.title.text, xLabelText);
+            tc.verifyEqual(p.layout.yaxis1.title.text, yLabelText);
+        end
     end
 end

plotly/plotlyfig_aux/helpers/extractHeatmapAxisData.m

@@ -27,7 +27,9 @@
         "tickvals", string(axis_data.(axisName + "DisplayData")), ...
         "autotick", false, ...
         "tickson", "boundaries", ...
-        "title", axis_data.(axisName + "Label"), ...
+        "title", struct( ...
+            "text", string(axis_data.(axisName + "Label")) ...
+        ), ...
         "titlefont", struct( ...
             "color", "black", ...
             "size", axis_data.FontSize*1.3, ...