graphics: option to change primary monitor before launching game (#608)

## Description of change

Adds `-mainmonitor` option which changes the monitor layout before
launching the game. This is much more reliable than the old `-monitor`
option which operated at DX9 level. This works for TDJ/UFC subscreens,
for example.

Rename `-monitor` option to `-dx9mainadapter` to discourage use.
`-monitor` will continue to work, of course.

Changing of primary monitor happens first before any orientation changes
/ refresh rate changes, which means those options will result in the
logically correct configuration.

Create a new option category for `Monitor` (rotate, refresh rate, etc).

Add a monitor selection widget for `-mainmonitor` option in the
configurator.

Improve how we log names of monitors in the log during boot - should be
less of "Generic PnP Monitor" after this.

src/spice2x/cfg/option.h

@@ -20,6 +20,7 @@ enum class OptionPickerType {
     CpuAffinity,
     FilePath,
     DirectoryPath,
+    Monitor,
 };
 
 struct OptionDefinition {