Add image upload support (/image API)

[tanysheng]

Documentation: https://serpapi.com/image-api

[tanysheng]

To maintain supports for Node 7.x and newer, otherwise we could consider Node 18 which fetch is available natively

[strzibny]

Timeout and network errors are converted into generic ImageApiError... RequestTimeoutError, DNS errors, TLS failures, and connection reset shouldn't be just ImageApiError. We should fix that.

I also noticed that JSON response with error key is returned with HTTP 200 and resolves as a successful response, but the client should understand there is an error. But that's the whole library problem.

[tanysheng]

Timeout and network errors are converted into generic ImageApiError... RequestTimeoutError, DNS errors, TLS failures, and connection reset shouldn't be just ImageApiError. We should fix that.

I also noticed that JSON response with error key is returned with HTTP 200 and resolves as a successful response, but the client should understand there is an error. But that's the whole library problem.

Good catch. I removed ImageApiError, so the error is now consistent with the search method. It still has some flaws (e.g. raw JSON), and I plan to fix them together in another PR, including cases where it's successful when HTTP 200 error is returned.

[strzibny]

It's fine to address in a follow-up. Can you rebase and make the test green?

[tanysheng]

It's fine to address in a follow-up. Can you rebase and make the test green?

@strzibny Done