PLT-4403 Add server-based channel autocomplete, search and paging (#4585)

* Add more channel paging API

* Add channel paging support to client

* Add DB channel search functions

* Add API for searching more channels

* Add more channel search functionality to client

* Add API for autocompleting channels

* Add channel autocomplete functionality to the client

* Move to be deprecated APIs to their own file

* Final clean-up

* Fixes related to feedback

* Localization changes

* Add unit as suffix to timeout constants

webapp/client/client.jsx

@@ -1362,6 +1362,7 @@ export default class Client {
         this.track('api', 'api_channel_get');
     }
 
+    // SCHEDULED FOR DEPRECATION IN 3.7 - use getMoreChannelsPage instead
     getMoreChannels(success, error) {
         request.
             get(`${this.getChannelsRoute()}/more`).
@@ -1371,6 +1372,34 @@ export default class Client {
             end(this.handleResponse.bind(this, 'getMoreChannels', success, error));
     }
 
+    getMoreChannelsPage(offset, limit, success, error) {
+        request.
+            get(`${this.getChannelsRoute()}/more/${offset}/${limit}`).
+            set(this.defaultHeaders).
+            type('application/json').
+            accept('application/json').
+            end(this.handleResponse.bind(this, 'getMoreChannelsPage', success, error));
+    }
+
+    searchMoreChannels(term, success, error) {
+        request.
+            post(`${this.getChannelsRoute()}/more/search`).
+            set(this.defaultHeaders).
+            type('application/json').
+            accept('application/json').
+            send({term}).
+            end(this.handleResponse.bind(this, 'searchMoreChannels', success, error));
+    }
+
+    autocompleteChannels(term, success, error) {
+        request.
+            get(`${this.getChannelsRoute()}/autocomplete?term=${encodeURIComponent(term)}`).
+            set(this.defaultHeaders).
+            type('application/json').
+            accept('application/json').
+            end(this.handleResponse.bind(this, 'autocompleteChannels', success, error));
+    }
+
     getChannelCounts(success, error) {
         request.
             get(`${this.getChannelsRoute()}/counts`).