Revert "HotloadManager disposes Hotload instance, was stopping assembly unloading"
This reverts commit 1d83455903d1b9995c5680c933c49738ce22f149.
Revert "LoadContext.Unload also unloads all it's IsolatedAssemblyContext"
This reverts commit 672aabaadd48f649bf3c38068d4efe2e2c55780e.