Automatic channel category sorting (#30866)

* Automatic channel category sorting

* Fix types

* AIed

* Fix issue where categories are updated for all users

* Move all logic to server, clean up

* PR feedback

* Fix lint

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

webapp/platform/types/src/channels.ts

@@ -69,6 +69,7 @@ export type Channel = {
     policy_id?: string | null;
     banner_info?: ChannelBanner;
     policy_enforced?: boolean;
+    default_category_name?: string;
 };
 
 export type ServerChannel = Channel & {

webapp/platform/types/src/config.ts

@@ -112,6 +112,7 @@ export type ClientConfig = {
     EnableUserDeactivation: string;
     EnableUserTypingMessages: string;
     EnforceMultifactorAuthentication: string;
+    ExperimentalChannelCategorySorting: string;
     ExperimentalClientSideCertCheck: string;
     ExperimentalClientSideCertEnable: string;
     ExperimentalEnableAuthenticationTransfer: string;
@@ -822,6 +823,7 @@ export type ExperimentalSettings = {
     DisableWakeUpReconnectHandler: boolean;
     UsersStatusAndProfileFetchingPollIntervalMilliseconds: number;
     YoutubeReferrerPolicy: boolean;
+    ExperimentalChannelCategorySorting: boolean;
 };
 
 export type AnalyticsSettings = {