merge_pr_46456

[wdspec] Add wdspec tests for network.continueRequest

Depends on D209540

Differential Revision: https://phabricator.services.mozilla.com/D209541

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1850680
gecko-commit: 9a98ace82049ec685ce68c7a2b1c7f877be06532
gecko-reviewers: webdriver-reviewers, whimboo