The offline cargo feature is backwards

[fasterthanlime]

See also rust-headless-chrome/rust-headless-chrome#489 (which is blocked on this)

One problem with the current offline feature is that ureq (and an outdated version of rustls) get pulled in even if offline is enabled, since there's no way to "depend on a crate if a cargo feature is disabled".

Instead, there should be an online feature (it could be on by default if you want), which in turns pulls in ureq.

This is a breaking change for both auto_generate_cdp and rust-headless-chrome.