1052732: Updated latest theme references

Author: RahulSF4846

package.json

@@ -11,6 +11,7 @@
   },
   "dependencies": {
     "@syncfusion/ej2-react-spreadsheet": "*",
+    "@syncfusion/ej2-material-theme": "*",
     "react": "^19.2.5",
     "react-dom": "^19.2.5"
   },

src/index.css

@@ -1,10 +1 @@
-@import '../node_modules/@syncfusion/ej2-base/styles/material.css';
-@import '../node_modules/@syncfusion/ej2-inputs/styles/material.css';
-@import '../node_modules/@syncfusion/ej2-buttons/styles/material.css';
-@import '../node_modules/@syncfusion/ej2-splitbuttons/styles/material.css';
-@import '../node_modules/@syncfusion/ej2-lists/styles/material.css';
-@import '../node_modules/@syncfusion/ej2-navigations/styles/material.css';
-@import '../node_modules/@syncfusion/ej2-popups/styles/material.css';
-@import '../node_modules/@syncfusion/ej2-dropdowns/styles/material.css';
-@import '../node_modules/@syncfusion/ej2-grids/styles/material.css';
-@import '../node_modules/@syncfusion/ej2-react-spreadsheet/styles/material.css';
+@import '../node_modules/@syncfusion/ej2-material-theme/styles/spreadsheet/index.css';