refactor: convert rowIdentity to signal input

Author: spike-rabbit

projects/ngx-datatable/src/lib/components/datatable.component.html

@@ -53,7 +53,7 @@
       [innerWidth]="_innerWidth()"
       [bodyHeight]="bodyHeight()"
       [selectionType]="selectionType()"
-      [rowIdentity]="rowIdentity"
+      [rowIdentity]="rowIdentity()"
       [rowClass]="rowClass()"
       [selectCheck]="selectCheck()"
       [displayCheck]="displayCheck()"

projects/ngx-datatable/src/lib/components/datatable.component.ts

@@ -838,15 +838,15 @@ export class DatatableComponent<TRow extends Row = any>
    *
    * (`fn(x) === fn(y)` instead of `x === y`)
    */
-  @Input() rowIdentity: (x: RowOrGroup<TRow>) => unknown = x => {
+  readonly rowIdentity = input<(x: RowOrGroup<TRow>) => unknown>(x => {
     if (this.groupRowsBy()) {
       // each group in groupedRows are stored as {key, value: [rows]},
       // where key is the groupRowsBy index
       return (x as Group<TRow>).key ?? x;
     } else {
       return x;
     }
-  };
+  });
 
   /**
    * Creates a map with the data grouped by the user choice of grouping index