Migrate to chromiumembeddedframework.runtime Nuget packages

[amaitland]

We currently already use those packages for the NETCore packages and within the project itself for the example projects.

Up until now the older cef.redist packages has been used for the .Net Framework packages. Unfortunately we've exceeded the MyGet feed limit of 500mb, so need to remove the older packages and migrate to the newer ones to reduce duplication.

The older cef.redist pacakges will no longer be updated.

cefsharp/cef-binary#93

• Update nuget packages

[amaitland]

For those using older packages.config, make sure you upgrade the top level pacakges e.g. CefSharp.Wpf, CefSharp.WinForms, CefSharp.OffScreen. If you end up with references to cef.redist.x64 or cef.redist.x86 after upgrading then you can safely remove those packages (the should have an older version number).

The new package dependencies are:

• chromiumembeddedframework.runtime.win-x64
• chromiumembeddedframework.runtime.win-x86

The files contained within these packages are identical, just structured slightly differently to support .Net Core 3.1, .Net 5/6/7/8+.

The .props and .targets within these packages should be compatible without making any changes to your application directly.

[vittoso]

Unfortunately this breaks compatibility with Visual Studio 2017 as chromiumembeddedframework.runtime package requires NuGet 5.0.0 and VS2017 comes with NuGet Package Manager version 4.9.3 and it doesn't seem to be update-able.