[Feature][API] Add AST processors to public API

[kishtarn555]

Expose the three methods that:

• Generate opcode from AST
• Generate Java from AST
• Generate Pascal from AST

This is so other programmers can create their own programming languages that compile to KarelCode or transpiles to one of the official languages, but can enjoy of the extended features from AST (tags, continue, break, functions, strict types)