feat(integrations): add Apify integration

[lev-goryachev]

Summary

• Apify: full integration with 120 methods covering the complete Apify REST API v2
  • Actor runs: start, stop, resurrect, charge events, get run info/log/output
  • Actors: list, get, build, delete, manage versions and builds
  • Datasets: create, read, update, delete, list items
  • Key-value stores: get/set/delete records, list keys
  • Request queues: add/get/delete requests, manage queue state
  • Webhooks: create, list, update, delete, dispatch
  • Schedules: create, list, update, delete
  • Tasks: create, list, run, get last run
  • Store listings: search Apify store actors

Note for reviewer

Depends on the generic handler introduced in PR #256 — merge that first.