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/user.go

@@ -596,6 +596,16 @@ func (u *User) AddNotifyProp(key string, value string) {
 	u.NotifyProps[key] = value
 }
 
+func (u *User) SetCustomStatus(cs *CustomStatus) {
+	u.MakeNonNil()
+	u.Props[UserPropsKeyCustomStatus] = cs.ToJson()
+}
+
+func (u *User) ClearCustomStatus() {
+	u.MakeNonNil()
+	u.Props[UserPropsKeyCustomStatus] = ""
+}
+
 func (u *User) GetFullName() string {
 	if u.FirstName != "" && u.LastName != "" {
 		return u.FirstName + " " + u.LastName