[IMPROVEMENT] Maintenance refactoring

Wraps previously global state to a single newly-defined struct named CONTEXT in src/types.h and moves all functions that previously modified CONTEXT to a new module named src/types.c. The functions are now all prefixed with the "class"'s name in an oop style. This is to separate the context from the tracing functionality and encapsulate the context so we reason about its data accesses for future optimizations.

Also some minor changes such as variable renames.

This pull request aims to organize our state so i can perform modifications to optimize build_recorder in the future.