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 499f7eaca8.

* Update i18n strings

model/feature_flags.go

@@ -18,6 +18,10 @@ type FeatureFlags struct {
 
 	// Toggle on and off support for Collapsed Threads
 	CollapsedThreads bool
+
+	// Toggle on and off support for Custom User Statuses
+	CustomUserStatuses bool
+
 	// Feature flags to control plugin versions
 	PluginIncidentManagement string `plugin_id:"com.mattermost.plugin-incident-management"`
 }
@@ -27,6 +31,7 @@ func (f *FeatureFlags) SetDefaults() {
 	f.TestBoolFeature = false
 	f.CloudDelinquentEmailJobsEnabled = false
 	f.CollapsedThreads = false
+	f.CustomUserStatuses = false
 	f.PluginIncidentManagement = "1.4.0"
 }