Enormous refactor (v2.1.1)

Strict typed responses

• Types for all responses in OpenAPI spec
• Standardized methods to correspond tonlib TL scheme: /api/v2/runGetMethodStd, /api/v2/getTransactionsStd.

Completely reorganized project structure

• All methods are extracted to separate handlers
• Flexible configuration for methods
• POST version of every GET method
• JsonRPC now uses POST versions of methods

Other improvements

• Optimized and tiny Docker image
• Partial coverage with tests
• Improved logging with flexible configuration
• Separate cache for every handler with configurable expiration time