Improved external dialog to no longer extend onto other monitors

[AKruimink]

Describe the changes you have made to improve this project

• Added a check for window state in CreateModalExternalWindow
• Added a border offset to take in account the overhang on both sides of the window when maximized causing a dialog to extend outside of the screen bounds.
• Fix SetupExternalDialogWindow
  Use the monitor from where the owner stays and use the working area for the dialog size properties and remove also the left and right border.
• Simplify getting the working area from current monitor with new extension method GetMonitorWorkSize
  Use this method in both variants SetupExternalDialogWindow and CreateModalExternalWindow which also fixes the main issue without calculating an offset by hand.

Closed Issues

Closes #3538

[AKruimink]

Few things.

1. With the way it currently works the offset is always calculated, this could still be changed to only get calulated on Maximized state, any preference?

2. SetupExternalDialogWindow seems to maximize at all times, i wasnt sure if it required the change as well and thus has been left out, a minor issue with the current setup is when a user has monitors with different resolutions the PrimaryScreenWidth might not fit.

[AKruimink]

Changed the check regardless, might be less pretty to look at, but it's not worth creating an offset each time when most of the time it's not used anyways.

[AKruimink]

@punker76 or @timunie The CreateModalExternalWindow has been fixed and seems to be working.

For the SetupExternalDialogWindow i can't really find a proper way of doing it. The only ways i could come up with us by using Screen but would require Windows.Forms which i think is a bad idea, or you end up having to wrap around pinvoke and do it that way, which doesnt seem great either.

So the only options im further left with is.

1. leave it as is, SystemParameters.PrimaryScreen(Width/Height) will be set, and if a user has a smaller secondary screen you will have the overlap onto the other monitor (or the opposite if the screen is bigger).

2. Add optional parameters to the method that allows for custom sizes, or if left empty just use the SystemParameters.PrimaryScreen(Width/Height) .

option 2 would not persé fix the issue but would offer more flexibility at the least.

Any input would be appreciated

[punker76]

@AKruimink I have a solution for it and will check in later.

[punker76]

@AKruimink your changes have been merged, thanks for your contribution 👍