[kql] Fix literal toKqlExpression to escape special characters and keywords (#162195)

## Summary

`toKqlExpression` support was added in
https://github.com/elastic/kibana/pull/161601. This PR Fixes a bug with
`toKqlExpression` that did not properly escape special characters and
keywords.

Without this fix, you could get into a problematic situation like the
following:

```ts
const node = fromKueryExpression('field: bar\\*');
const result = toKqlExpression(node); // 'field: bar*'
```

This was incorrect, since if we were then to call `fromKueryExpression`
on this value again, we would get a wildcard (`bar*`), not a string.

### Checklist

- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

packages/kbn-es-query/src/kuery/functions/range.test.ts

@@ -356,7 +356,7 @@ describe('kuery functions', () => {
         expect(result).toMatchInlineSnapshot(`"byt* > 1000"`);
       });
 
-      test('with wildcard field & wildcard value', () => {
+      test('with wildcard field & value', () => {
         const node = nodeTypes.function.buildNode(
           'range',
           'byt*',
@@ -364,7 +364,7 @@ describe('kuery functions', () => {
           '100*'
         ) as KqlRangeFunctionNode;
         const result = range.toKqlExpression(node);
-        expect(result).toMatchInlineSnapshot(`"byt* > 100*"`);
+        expect(result).toMatchInlineSnapshot(`"byt* > 100\\\\*"`);
       });
     });
   });

packages/kbn-es-query/src/kuery/node_types/literal.test.ts

@@ -42,6 +42,18 @@ describe('kuery node types', () => {
         const result = toKqlExpression(node);
         expect(result).toBe('"foo"');
       });
+
+      test('reserved chars', () => {
+        const node = buildNode('():<>"*');
+        const result = toKqlExpression(node);
+        expect(result).toBe('\\(\\)\\:\\<\\>\\"\\*');
+      });
+
+      test('reserved keywords', () => {
+        const node = buildNode('foo and bar not baz or qux');
+        const result = toKqlExpression(node);
+        expect(result).toBe('foo \\and bar \\not baz \\or qux');
+      });
     });
   });
 });

packages/kbn-es-query/src/kuery/node_types/literal.ts

@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-import type { KueryNode } from '../types';
+import { type KueryNode, escapeKuery } from '..';
 
 export const KQL_NODE_TYPE_LITERAL = 'literal';
 
@@ -35,5 +35,5 @@ export function toElasticsearchQuery(node: KqlLiteralNode) {
 }
 
 export function toKqlExpression(node: KqlLiteralNode): string {
-  return node.isQuoted ? `"${node.value}"` : `${node.value}`;
+  return node.isQuoted ? `"${node.value}"` : escapeKuery(`${node.value}`);
 }