Support using as a library

[puff]

Currently, everything is built into a standalone executable. It would be nice to be able to use the project as a library to allow a more extensible pipeline.

Tasks to be done:

• Split Core into separate projects.
• Make Core completely separated from the pipeline.
  - For example, IO namespace uses DevirtualizationContext from the pipeline. We should move IO away from the Core namespace.
• Fix the internal access modifier spam.
• Split MethodDevirtualizer stage into MethodDisassembler and MethodRecompiler stages.
  - Decouple VMMethod and other VM architecture from CIL and keep them more VMIL.
  - Allows other stages to modify instructions before recompilation (i.e. Fixers or Data Devirtualization)
• Move Devirtualization namespace to its own project and implement an IPipeline.
  - Decentralizes the pipeline and allow for more pipelines to be created and used.