Mobile matrix footer - addRowLocation - top #9425 (#9427)

* Mobile matrix footer - addRowLocation - top #9425
Fixed #9425

* #9410 update screenshots

Author: novikov82

packages/survey-core/src/default-theme/blocks/sd-matrixdynamic.scss

@@ -7,8 +7,25 @@
   z-index: 12;
 }
 
+.sd-question--mobile .sd-matrixdynamic__footer::before
+{
+  z-index: 12;
+  content: " ";
+  display: block;
+  position: relative;
+  height: 1px;
+  background-color: $border-light;
+  left: calcSize(-3);
+  top: calcSize(-1);
+  width: calc(100% + 6 * #{$base-unit});
+  z-index: 12;
+}
+
 .sd-matrixdynamic__footer:first-child {
   padding-bottom: calcSize(2);
+  &::before {
+    display: none;
+  }
 }
 
 .sd-matrixdynamic__footer {

packages/survey-core/src/default-theme/blocks/sd-table.scss

@@ -615,6 +615,9 @@
     tr:not(.sd-table__row--expanded)::after {
       bottom: 0;
     }
+    tr:last-of-type::after {
+      display: none
+    }
 
     tfoot tr {
       padding-top: calcSize(5);

visualRegressionTests/tests/defaultV2/etalons/responsiveness-matrixdynamic-add-top.png

@@ -267,12 +267,35 @@ frameworks.forEach(framework => {
             addRowText: "Add a New Record",
             rowCount: 2,
           },
+          {
+            type: "matrixdynamic",
+            name: "frameworks1",
+            title: "Please tells us your opinion about JavaScript MVVM frameworks.",
+            columns: [
+              {
+                "name": "Column 1",
+                "title": "Framework"
+              },
+              {
+                "name": "Column 2",
+                "title": "How long do you use it?"
+              },
+              {
+                "name": "Column 3",
+                "title": "What is main strength?"
+              }
+            ],
+            addRowText: "Add a New Record",
+            rowCount: 2,
+            "addRowLocation": "top"
+          },
         ]
       });
       await ClientFunction(() => {
         document.body.focus();
       })();
-      await takeElementScreenshot("responsiveness-matrixdynamic.png", Selector(".sd-question"), t, comparer);
+      await takeElementScreenshot("responsiveness-matrixdynamic.png", Selector(".sd-question").nth(0), t, comparer);
+      await takeElementScreenshot("responsiveness-matrixdynamic-add-top.png", Selector(".sd-question").nth(1), t, comparer);
     });
   });
   test("Check matrixdynamic on small screen with errors", async (t) => {