[MM-34076] Add Plugin API User custom status (#17435)

* add missing client for custom user status

* add custom user status plugin api

* update based on feedback review

* add GetCustomStatus

* update interfaces

model/user.go

@@ -621,6 +621,15 @@ func (u *User) SetCustomStatus(cs *CustomStatus) error {
 	return nil
 }
 
+func (u *User) GetCustomStatus() *CustomStatus {
+	var o *CustomStatus
+
+	data := u.Props[UserPropsKeyCustomStatus]
+	_ = json.Unmarshal([]byte(data), &o)
+
+	return o
+}
+
 func (u *User) ClearCustomStatus() {
 	u.MakeNonNil()
 	u.Props[UserPropsKeyCustomStatus] = ""