Adding a run in editor feature

Is your feature request related to a problem? Please describe.
When I want to debug a new project on xenko, it always opens a new window,

The first issue with this comes from the fact that it creates a new window.
It isn't a good thing for people with only one screen, since it makes it harder to see the editor while playing when the game window hides the editor window

The second and biggest issue is that on laptops having integrated graphics + an nvidia gpu , it tends to confuse the intel technology not knowing wether it should use the integrated graphics or the nvidia drivers for the newly opened process (in my case, it was chosing the worst option, the integrated graphics for the game instead of my gtx 1060 while using the 1060 for the editor, which forced me to always manually set for all the binaries new projects the default gpu to use, which shouldn't be required when using a game engine)

Describe the solution you'd like
Having an option allowing to directly play the game in the editor, the same way as Unity Engine, Unreal Engine and Lumberyard Engine

it would allow to still look at the engine while playing (and maybe allow to edit in real time variables)
and allow to set only once the editor to use the nvidia gpu and all the projects would properly work with the high performances gpu without setting each executable manually

Describe alternatives you've considered
I don't really know any possible alternative that could fix the second issue I mentionned, but for the first issue, it should be possible to still use an other process but instead of making a new window simply rendering it in the editor.

Additional context
Here is an example where the integrated gpu was automatically chosed instead of my gtx 1060 because of the way it works (it's saying that no app except the editor is using the nvidia gpu, which means that because the game is an external process it automatically uses the integrated graphics)

it could indeed be possible to make it so that the pc always uses the nvidia gpu in the system settings, but if there is this feature automatically using the integrated gpu it's because it's useful and necessary since it allows to reduce heat and power consumptions, which is normal for gaming laptops so we should be able to use properly the xenko engine without having to modify it and just add an exception for the xenko editor

The issue names no files, tests, or entry points; start by locating the editor's play/debug launch flow and how it creates the external game window. Done would mean an option to render the game in the editor, keep editor visibility during play, and avoid separate GPU selection for each project.