Bug/accessibility 5 (#7008)

* fixing 6946 and 6796(second part)

* fix for https://github.com/microsoft/azuredatastudio/issues/6726

* comments cleanup

* taking PR comments

* adding strong border for HC focus

* convert to string template

src/sql/base/browser/ui/table/formatters.ts

@@ -4,6 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { escape } from 'sql/base/common/strings';
+import { localize } from 'vs/nls';
 
 export class DBCellValue {
 	displayValue: string;
@@ -77,6 +78,19 @@ export function slickGridDataItemColumnValueExtractor(value: any, columnDef: any
 	};
 }
 
+/**
+ * Alternate function to provide slick grid cell with ariaLabel and plain text
+ * In this case, for no display value ariaLabel will be set to specific string "no data available" for accessibily support for screen readers
+ * Set 'no data' lable only if cell is present and has no value (so that checkbox and other custom plugins do not get 'no data' label)
+ */
+export function slickGridDataItemColumnValueWithNoData(value: any, columnDef: any): { text: string; ariaLabel: string; } {
+	let displayValue = value[columnDef.field];
+	return {
+		text: displayValue,
+		ariaLabel: displayValue ? escape(displayValue) : ((displayValue !== undefined) ? localize("tableCell.NoDataAvailable", "no data available") : displayValue)
+	};
+}
+
 /** The following code is a rewrite over the both formatter function using dom builder
  * rather than string manipulation, which is a safer and easier method of achieving the same goal.
  * However, when electron is in "Run as node" mode, dom creation acts differently than normal and therefore