Improve type-safety: automate generation of API-related TypeScript types

[brojd]

Problem

Problem and context are described in #3330 .

This issue is about step 3):
Automate generation of types (e.g. on prepush Git hook or similar). This way if changes in API breaks frontend, frontend build will automatically fail preventing us from introducing the bug

Acceptance criteria

• anytime Python models are changed, API-related TypeScript types are regenerated and saved in grafana-plugin directory

Outcome

• better type-safety in code
• being able to catch type errors during development before they reach prod (shift left)
• better developer experience thanks to increased number of type declarations and improved intellisense