Port V3.22.0 Changes to V4

[CharliePoole]

Primary Changes are listed in the 3.22.0 release on github and involve...

1. Support for MTP
2. Use of an instance of AssemblyLoadContext rather than our custom AssemblyLoadContext
3. Engine recognizes UseDefaultAssemblyLoadContext setting to use the default AssemlbyLoadContext rather than creating a searate instance. Currently not exposed as a console option.

Additional tests will also be added and the CI scripts may need to be updated.

[CharliePoole]

This issue has been resolved in version 4.0.0-beta.2

The release is available on:
GitHub.
NuGet packages are also available NuGet.org and
Chocolatey Packages may be found at Chocolatey.org