Fix timelion vis escapes single quotes (#84196) (#84230)

* Remove string escaping

* Add unit test

src/plugins/vis_type_timelion/public/to_ast.test.ts

@@ -37,4 +37,10 @@ describe('timelion vis toExpressionAst function', () => {
     const actual = toExpressionAst(vis);
     expect(actual).toMatchSnapshot();
   });
+
+  it('should not escape single quotes', () => {
+    vis.params.expression = `.es(index=my*,timefield="date",split='test field:3',metric='avg:value')`;
+    const actual = toExpressionAst(vis);
+    expect(actual).toMatchSnapshot();
+  });
 });

src/plugins/vis_type_timelion/public/to_ast.ts

@@ -21,14 +21,12 @@ import { buildExpression, buildExpressionFunction } from '../../expressions/publ
 import { Vis } from '../../visualizations/public';
 import { TimelionExpressionFunctionDefinition, TimelionVisParams } from './timelion_vis_fn';
 
-const escapeString = (data: string): string => {
-  return data.replace(/\\/g, `\\\\`).replace(/'/g, `\\'`);
-};
-
 export const toExpressionAst = (vis: Vis<TimelionVisParams>) => {
+  const { expression, interval } = vis.params;
+
   const timelion = buildExpressionFunction<TimelionExpressionFunctionDefinition>('timelion_vis', {
-    expression: escapeString(vis.params.expression),
-    interval: escapeString(vis.params.interval),
+    expression,
+    interval,
   });
 
   const ast = buildExpression([timelion]);