[WebView] Support deployment on Windows, macOS, and Linux

[JoshEngebretson]

The embedded Chromium WebView needs to be able to be deployed with an Atomic application on desktop. Once this issue is out of staging we can fill this in more, in the meantime I'll give it a difficulty of 4, quite a bit involved.

[darrylryan]

@JoshEngebretson I've had a go trying to get the web view working with C#

So far I I've managed to figure out this much:

I went into /Script/AtomicNET/AtomicNETProject.json and added this to get the bindings into C#: "$ATOMIC_ROOT$/Artifacts/Build/Source/Generated/CSharp/Packages/AtomicPlayer/Managed/"

Then I went into "/Script/AtomicNET/AtomicNET/Core/AtomicNET.cs" and added this so the module is inititalized: #if ATOMIC_DESKTOP
WebViewModule.Initialize();

That got me the managed bit but I found the native bit was missing so I went into /Script/Packages/AtomicNETNative/Package.json and added: "dependencies" : ["Script/Packages/WebView"]

and then in "/Source/AtomicNET/NETNative/CMakeLists.txt" I added "${CSATOMICDIR}/WebView/Native/.cpp ${CSATOMICDIR}/WebView/Native/.h )"

and added "AtomicWebView" to target_link_libraries

This seems to have got me most of the way, in that the managed wrapper is working and intellisense finds the classes, and the native DLL has the web view code - the problem is I am still missing the actual object code for the CEF. I think possibly I just need to point a path or two somewhere to get it to pull in CEF but I am not sure what/where. :S