Improve high-dpi display

[sasumner]

Fix #8115 (and probably others)

Seems to improve things on high-dpi monitors? (without any otherwise obvious problems)
Here's my result (a definite improvement) -- perhaps the screenshot removes some of the crispness of reality, though!
On the left is N++ 7.9.2; on the right is the result from this PR -- font size settings are the same for each.
This is running on Win10.
Would appreciate if others would try on various OS and monitor situations!

Credit (or blame) to @xianyun666

[chcg]

See https://docs.microsoft.com/en-us/windows/win32/hidpi/high-dpi-desktop-application-development-on-windows

Per-Monitor V1 DPI awareness mode (PMv1) was introduced with Windows 8.1. This DPI awareness mode is very limited and only offers the functionality listed below. It is recommended that desktop applications use Per-Monitor v2 awareness mode, supported on Windows 10 1703 or above.

So maybe "PerMonitorV2" might be even better on modern Win10 versions.

[sasumner]

@chcg said:

So maybe "PerMonitorV2" might be even better on modern Win10 versions.

Let's try it! (it is in 80d4780)

[donho]

@sasumner
Could you confirm that you can still reproduce the problem that @xianyun666 have mentioned?

[sasumner]

Could you confirm that you can still reproduce the problem that @xianyun666 have mentioned?

Interestingly, with PerMonitorV2, this time the bad effects were lessened, so I missed them.
But, yes, with V2 there are some bad UI elements...

So, I'll back this PR off to only use PerMonitor where I haven't yet seen any bad effects.
But it would be nice if many others could try it as well!

Here's a new screenshot, again with PerMonitor on my high-dpi screen, and again with 7.9.2 on the left, and the PerMonitor version of this PR on the right:

[sasumner]

Note: 0cec1bd removes PerMonitorV2 and restores PerMonitor

Sorry for the flip-flopping and possible confusion it generates.

[donho]

But, yes, with V2 there are some bad UI elements...

Could you provide the screen shot please?

[sasumner]

Could you provide the screen shot please? (using PerMonitorV2)

Ok, so to make screenshots I put PerMonitorV2 back in place.
And I have no explanation for this, but it looks A LOT worse than when I looked at it yesterday or even earlier today.
But here are some of the bad UI examples:

Find when opened onto a high-dpi monitor:

Find when opened onto a non-high-dpi monitor:

Shortcut Mapper when opened onto a high-dpi monitor:

Shortcut Mapper when opened onto a non-high-dpi monitor:

[donho]

Thank you very much @sasumner for your screenshots.
I don't know such display bug from Windows or Notepad++ - or it's due to part of your system (your OS) is not updated.
In any case, let's do it without V2.

[donho]

In fact, with V2 render the better standard GUI. OTOH, all the non standard GUI parts are f*cked up.