Custom status feature (#16835)

* Create the system console setting and send to webapp

* MI-1145: Add custom status APIs

* MI-1145 Add slash commands to set and clear status

* Add validation for custom status API

* Trim custom status message

* Code refactoring

- Run gofmt

- Rename constants

* Remove sendUserUpdated webhook event

* Fix recent custom status length

* Update error conditions

* Disable /status slash command when config setting is off

* MI-1155: Create the feature flag for custom status APIs and slash commands

* Move recent custom statuses to user preferences (#7)

* Move recent custom statuses to user preferences

* Code refactoring and feedback changes

* Update slash command text and emoji regex

* Make the custom status feature flag off by default

* Update SetCustomStatus, handle recents not set better

* Update status codes

* Update slash command handling

* Add telementry settings

* Fix i18n order

* Revert "Fix i18n order"

This reverts commit 499f7eaca8180336f5bcca360cc0133365899e08.

* Update i18n strings

model/preference.go

@@ -40,6 +40,12 @@ const (
 	PREFERENCE_NAME_LAST_CHANNEL = "channel"
 	PREFERENCE_NAME_LAST_TEAM    = "team"
 
+	PREFERENCE_CATEGORY_CUSTOM_STATUS            = "custom_status"
+	PREFERENCE_NAME_RECENT_CUSTOM_STATUSES       = "recent_custom_statuses"
+	PREFERENCE_NAME_CUSTOM_STATUS_TUTORIAL_STATE = "custom_status_tutorial_state"
+
+	PREFERENCE_CUSTOM_STATUS_MODAL_VIEWED = "custom_status_modal_viewed"
+
 	PREFERENCE_CATEGORY_NOTIFICATIONS = "notifications"
 	PREFERENCE_NAME_EMAIL_INTERVAL    = "email_interval"