Split `generate handlers` into multiple tools

[ghost]

Tool generate handlers is getting too complex. It should be split into multiple ones:

• scan controllers (name TBD) - parses controllers and dependencies, serializes result and saves it as .json (or some other format that is TBD).
• generate handlers - reads generated .json and creates a handlers package.
• generate routes - reads generated .json and creates routes package.
• generate reverse routes - reads generated .json and creates routes/reverse package.