Refactor/migrate/autocomplete database speabase specs to ts (#27837)

* refactor: migrate database/users_spec.js to ts

- migrate file autocomplete/database/users_spec.js to typescripts
- udpate system.d.ts data type adding type
for shouldHaveElasticsearchDisabled

* refactor: migrate users_in_channel_switcher_spec.js

- migrate file users_in_channel_switcher_spec to typescript
- fix issue with data type on file autocomplete/helpers.ts
function verifySuggestionAtChannelSwitcher
- fix issue with data type on file autocomplete/common_test.ts
function doTestQuickChannelSwitcher

* refactor: migrate users_in_message_input_box_spec to ts

- migrate file database/users_in_message_input_box_spec.js to typescript
- migrate file support/ui/suggestion_list.js to typescript and update
docs and type definitions
- update references to doTestPostextbox function
- update references to verifySuggestionAtPostTextbox function

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

e2e-tests/cypress/tests/integration/channels/autocomplete/database/users_in_channel_switcher_spec.ts

@@ -12,11 +12,11 @@
 
 import {getRandomLetter} from '../../../../utils';
 import {doTestQuickChannelSwitcher} from '../common_test';
-import {createSearchData} from '../helpers';
+import {createSearchData, SimpleUser} from '../helpers';
 
 describe('Autocomplete with Database - Users', () => {
     const prefix = getRandomLetter(3);
-    let testUsers;
+    let testUsers: Record<string, SimpleUser>;
 
     before(() => {
         cy.apiGetClientLicense().then(({isCloudLicensed}) => {

e2e-tests/cypress/tests/integration/channels/autocomplete/database/users_in_message_input_box_spec.ts

@@ -12,11 +12,11 @@
 
 import {getRandomLetter} from '../../../../utils';
 import {doTestPostextbox} from '../common_test';
-import {createSearchData} from '../helpers';
+import {createSearchData, SimpleUser} from '../helpers';
 
 describe('Autocomplete with Database - Users', () => {
     const prefix = getRandomLetter(3);
-    let testUsers;
+    let testUsers: Record<string, SimpleUser>;
 
     before(() => {
         cy.apiGetClientLicense().then(({isCloudLicensed}) => {

e2e-tests/cypress/tests/integration/channels/autocomplete/database/users_spec.ts

@@ -12,12 +12,12 @@
 
 import {getRandomLetter} from '../../../../utils';
 import {doTestDMChannelSidebar, doTestUserChannelSection} from '../common_test';
-import {createSearchData} from '../helpers';
+import {createSearchData, SimpleUser} from '../helpers';
 
 describe('Autocomplete with Database - Users', () => {
     const prefix = getRandomLetter(3);
-    let testUsers;
-    let testTeam;
+    let testUsers: Record<string, SimpleUser>;
+    let testTeam: Cypress.Team;
 
     before(() => {
         cy.apiGetClientLicense().then(({isCloudLicensed}) => {