feat(Mattermost Node): Add support for Channel Search (#2687)

* Squashed commit of the following:

commit 9f76bdca9b4af4fd3ee429d1c381c3ed5529434c
Author: Matt Walther <matt@mashio.net>
Date:   Sun Jan 16 16:40:34 2022 -0600

    Mattermost Channel Search

* Add more boilerplate so Search action renders

* Changed order of search to make the operations alphabetical

* ⚡ Add pagination

Co-authored-by: Jonathan Bennetts <jonathan.bennetts@gmail.com>
Co-authored-by: ricardo <ricardoespinoza105@gmail.com>

packages/nodes-base/nodes/Mattermost/v1/actions/channel/search/index.ts

@@ -0,0 +1,7 @@
+import { search as execute } from './execute';
+import { channelSearchDescription as description } from './description';
+
+export {
+	description,
+	execute,
+};