CI: add linters & code formatters

[spicyfalafel]

• [x] snapshot tests structure: └── aidbox_sdk ├── snapshots │   └── typescript | | └── hl7-fhir-r4-core | | | └── Account.ts | | | └── ActivityDefinition.ts | | └── hl7-fhir-r5-core │   └── python
• [ ] typescript linter
• [ ] python linter
• [ ] c# linter
• [ ] java linter
• [ ] pre-commit hooks?
• [ ] code formatters?