Support for anti-Captcha.com

### Basic Stuff

- [x] Implement methods that don't use proxy until #26 solved

- [x] Manage APIKey

- [ ] hcaptcha cloudflare tests

- [ ] googlecaptcha tests

- [ ] microsoft funcaptcha tests

### Better Stuff

- [ ] Could be great if we could send it via the request, so it could be set on the program doing the request
Might be not doable until something else is done on Flaresolverr to manage this

### Documentation

- https://anti-captcha.com/apidoc/image
- https://anticaptcha.atlassian.net/wiki/spaces/API/pages/5505035/Examples

### Refs

Task of #24

Forking to https://github.com/xfouloux/FlareSolverr branch feature/anticaptcha

Review issue #24 and the linked anti-Captcha API documentation, then inspect the feature/anticaptcha branch in the referenced fork. Use the existing checklist to identify the remaining hCaptcha, Google CAPTCHA, and FunCaptcha tests, and clarify whether request-level configuration is feasible. Done means the remaining checklist items are resolved and the supported behavior is documented.

Written by the indexing model from the issue text.