DocumentWindow instead of ToolWindow

**Is your feature request related to a problem? Please describe.**
During debugging Visual Studio switches its view forth and back and then often the ResX Manager window comes to front and covers other code windows. You'll experience this with a multi monitor setup and if you have all monitors occupied by other code windows and additionally the ResX Manager open. I docked it to one of the windows, but then its behavior was similarly annoying. Googling didn't tell me anything about a possibly already implemented functionality.

**Describe the solution you'd like**
**Describe alternatives you've considered**
Currently I'm exploring AvalonDock for a while and I noticed that this behavior there and in Visual Studio (while very similar overall) seems to slightly differ between DocumentWindows and ToolWindows (or how ever they are called respectively) in that DocumentWindows work as expected and don't annoy. So I think it would be nice to switch from ToolWindow to DocumentWindow to mitigate the problem or at least to have an option or command to change this mode.