Feat symbol table: resolve circular dependency and introduce coroutines compilation

[ChAoSUnItY]

• [x] Resolve #23 - Finally, we have catched up the progress where we stopped last time :)
• [x] Resolve #24 - Additionally, we introduce coroutine compilation for multiple-file compilation, hopefully will speedup significantly
• [x] Resolve #25 - Last but not least, we refactored the project's structure so no more ambiguity for further development of CACS

Signed by @ChAoSUnItY