EVT_WU_RoamRadio should be included in list of wireless client events

[cameronr]

It doesn't look common, but I received these events together with no intervening EVT_WU_Connected event:

2020-04-27 19:58:51 DEBUG (MainThread) [aiounifi.websocket] {"meta":{"rc":"ok","message":"events"},"data":[{"user":"<<user_mac>>","ssid":"<>","hostname":"<>","ap":"<<ap_mac>>","duration":477,"bytes":19130891,"key":"EVT_WU_Disconnected","subsystem":"wlan","site_id":"<<site_id>>","time":1588042724000,"datetime":"2020-04-28T02:58:44Z","msg":"User[<<user_mac>>] disconnected from "<>" (7m 57s<<site_id>> connected, 18.24M bytes, last AP[<<ap_mac>>])","_id":"5ea79be852faff00f29407d2"},{"ap":"<<ap_mac>>","user":"<<user_mac>>","radio_from":"na","radio_to":"ng","channel_from":"36","channel_to":"11","key":"EVT_WU_RoamRadio","subsystem":"wlan","site_id":"<<site_id>>","time":1588042728065,"datetime":"2020-04-28T02:58:48Z","msg":"User[<<user_mac>>] roams from "channel 36(na)" to "channel 11(ng)" at AP[<<ap_mac>>]","_id":"5ea79be852faff00f29407d4"}]}

The result in Home Assistant is that wireless_connection was False, preventing the clearing of cancel_scheduled_update, causing my device to be set as not_home.

I think EVT_WU_RoamRadio should be included as a wireless client event so it can be picked up in HA.