Consolidate all 'extra' dynamic code into one dynamic assembly and add ability to save it

[TheModMaker]

There are two places where dynamic assemblies are used. One is for the .NET CodeCompiler for generating Delegate types for Lua methods. This always uses the same dynamic assembly. Second, there is a dynamic assembly in each Lua class. Neither of these can be saved.

Although it is unlikely these would be useful to outside users, it would make debugging internally easier if it was in one place that could be saved to view in a disassembler.

[TheModMaker]

Under newer .NET frameworks (e.g. .NET Core 3.1+), we can't save dynamically generated assemblies.