Supprt for MSH400 hub
* **Please explain your feature request in a one or two sentences.**
* Support for MSH400 hub

* **Is your feature request related to a problem? Please describe.**
* Smart Hub 400 is not supported

* **Any particular Meross devices that this relates to?**
* MSH400 has links to leak detector and humidity sensor

* **Anything else?**
* From Homebridge log:
[Smart Hub 400] is not supported, do create a github issue https://bit.ly/hb-meross-issues with info:
{"uuid":"2401128699411232080249e1e9eab71a","onlineStatus":1,"devName":"Smart Hub 400","devIconId":"device_msh400_un","bindTime":1711469805,"deviceType":"msh400","subType":"un","channels":[{}],"region":"eu","fmwareVersion":"4.5.15","hdwareVersion":"4.0.0","userDevIcon":"","iconType":1,"domain":"mqtt-eu-4.meross.com","reservedDomain":"mqtt-eu-4.meross.com","hardwareCapabilities":[],"firmware":"4.5.15","hbDeviceId":"2401128699411232080249e1e9eab71a","model":"MSH400"}

* **Anything even more to add?**
* Thank you :)