Make BMS Reboot possible from the web GUI

[StarkJohan]

I understand that BMS Reboot (not to be confused with Emulator Reboot) is now available over MQTT. As most other settings are available from the web GUI it would be a very nice addition to include the BMS Reboot here as well. Especially as not all users have connected the BE to a MQTT broker.

What?
Make it possible to reboot/power cycle the BMS (BMS_Power output) from the web GUI.

Why?
The function is there. It's available over MQTT. Not all users are using MQTT but most users probably have the web GUI activated.

How?
Add a button to the web server. Activating the actual BMS power cycle needs to be confirmed by an additional dialog just like the pause function is today to avoid mistakenly rebooting the BMS.