PowerMonitorControl toy

[yuyoyuppe]

Summary of the new feature/enhancement

Almost all modern monitors support out-of-the-box communication via DDC/CI protocol and expose their settings to it. That means we could:

• control "true" brightness/contrast/color-temperature and any other setting via hotkey, or set a dependcy on a time of day/weather forecast(e.g. cloudy/sunny);
• bind hotkeys to switch monitor input(HDMI/DVI/DP/...). very useful if you have multiple devices to control;
• introduce customizable setting profiles and an ability to interpolate between them.

Related: #48.

Proposed technical implementation details (optional)

Use SetVCPFeature and CapabilitiesRequestAndCapabilitiesReply.

[crutkas]

for being able to adjust the monitor's input, you swap input, how does swapping back work? would windows even see the monitor at that point?

[crutkas]

Tracking issue in #1052 as the main issue for PowerDisplay. the issues are xref'ed so we can refer back to it.