Improve type safety

[janbuchar]

• There are multiple opportunities throughout Crawlee to improve type safety and optionally introduce runtime validation:
  • Dataset items (CrawlingContext.pushData)
  • Key-value store content
  • Request.userData
  • Request routing labels
  • ? possibly somewhere else
• One option is allowing the user to declare some special types (DatasetItem, RequestLabel, ...) in a .d.ts file and using it for type checking
  • TanStack router utilizes a similar approach
• A safer and more versatile approach would be to accept standard-schema models (either via BasicCrawler or Configuration) and infer the types from those
  • this would also add runtime validation (in contrast to the .d.ts approach which is more of a gentleman agreement)

[B4nan]

Related: #1485