Add the ability to turn off power saving method

[Chinaski1]

Several users contacted our support team regarding a situation about periodic spikes in CPU usage. Customers have noticed the increased CPU consumption provided that AdGuard is in a rolled-up state. If you open the main menu from the tray, consumption is coming back to normal. The developers have suggested that the specified situation can be caused by automatic activation of the power-saving function. If so, it would be nice to add the ability to disable this function by yourself.

Customer ID

• 2606275
• Time in Logs: 15:0X, 16:0X and 18:4X at 22nd Oct 2020.
• What it looked like
• Main menu is opened