[Files] Do not doubly escape search queries (#159793)

## Summary

Closes https://github.com/elastic/kibana/issues/159783


### Checklist

Delete any items that are not applicable to this PR.

- [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


### For maintainers

- [x] This was checked for breaking API changes and was [labeled
appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

src/plugins/files/server/file_client/file_metadata_client/adapters/query_filters.ts

@@ -7,7 +7,7 @@
  */
 
 import { pipe, forEach } from 'lodash/fp';
-import { escapeKuery, KueryNode, nodeBuilder, nodeTypes } from '@kbn/es-query';
+import { KueryNode, nodeBuilder, nodeTypes } from '@kbn/es-query';
 
 import { getFlattenedObject } from '@kbn/std';
 
@@ -44,7 +44,7 @@ export function filterArgsToKuery({
         .map((value) =>
           nodeBuilder.is(
             `${attrPrefix}.${fieldName}`,
-            isWildcard ? nodeTypes.wildcard.buildNode(value) : escapeKuery(value)
+            isWildcard ? nodeTypes.wildcard.buildNode(value) : value
           )
         );
       kueryExpressions.push(nodeBuilder.or(orExpressions));
@@ -56,10 +56,7 @@ export function filterArgsToKuery({
       const andExpressions = values
         .filter(Boolean)
         .map((value) =>
-          nodeTypes.function.buildNode(
-            'not',
-            nodeBuilder.is(`${attrPrefix}.${fieldName}`, escapeKuery(value))
-          )
+          nodeTypes.function.buildNode('not', nodeBuilder.is(`${attrPrefix}.${fieldName}`, value))
         );
       kueryExpressions.push(nodeBuilder.and(andExpressions));
     }

src/plugins/files/server/file_share_service/internal_file_share_service.ts

@@ -13,7 +13,7 @@ import {
   ISavedObjectsRepository,
   SavedObjectsErrorHelpers,
 } from '@kbn/core/server';
-import { nodeBuilder, escapeKuery } from '@kbn/es-query';
+import { nodeBuilder } from '@kbn/es-query';
 import { UsageCounter } from '@kbn/usage-collection-plugin/server';
 import type {
   Pagination,
@@ -232,7 +232,7 @@ export class InternalFileShareService implements FileShareServiceStart {
       saved_objects: [share],
     } = await this.savedObjects.find<FileShare>({
       type: this.savedObjectsType,
-      filter: nodeBuilder.is(`${this.savedObjectsType}.attributes.token`, escapeKuery(token)),
+      filter: nodeBuilder.is(`${this.savedObjectsType}.attributes.token`, token),
     });
 
     if (!share) {

src/plugins/files/server/routes/file_kind/integration_tests/file_kind_http.test.ts

@@ -172,6 +172,23 @@ describe('File kind HTTP API', () => {
     expect(files3.length).toBe(2);
   });
 
+  test('can filter by mime type with special characters', async () => {
+    await createFile({ name: 'test', mimeType: 'image/x:123' });
+    await createFile({ name: 'test 2', mimeType: 'text/html' });
+
+    const {
+      body: { files },
+    } = await request
+      .post(root, `/api/files/files/${fileKind}/list`)
+      .send({
+        mimeType: 'image/x:123',
+      })
+      .expect(200);
+
+    expect(files.length).toBe(1);
+    expect(files[0]).toMatchObject({ name: 'test' });
+  });
+
   test('can filter by file extension', async () => {
     await createFile({ name: 'test', mimeType: 'image/png' });
     await createFile({ name: 'test 2', mimeType: 'text/html' });