Read-only bytecode tracking

**Purpose**

To allow a one-to-one byte-to-structure mapping. This format will yield read-only instances containing information that supports the mapping. This supports use cases that require knowledge of the actual bytecode values in the class file, rather than the structures the bytecode represents.

This will allow these structures to be represented in a fashion such as this:


**Prerequisites**

* Flesh out method instruction parsing
* Refactor reader classes to be extensible