refactor: remove ServiceWorker APIs from WebContents

[codebytere]

Description of Change

Refs #16704.

Remove ServiceWorker APIs (hasServiceWorker and unregisterServiceWorker) from WebContents. They haven't worked properly in some time and were not originally intended to exist on WebContents.

cc @deepak1556 @ckerr

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• tests are changed or added
• relevant documentation is changed or added
• PR title follows semantic commit guidelines
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: Removed hasServiceWorker and unregisterServiceWorker APIs from the WebContents modules.

[ckerr]

If the code was broken and nobody complained, IMO that says a lot for getting rid of this API.

However we should get public comment from the project long-timers before pulling the trigger

[deepak1556]

Originally the api were added to serve the purpose requested in #1331 (comment) , but as time progressed inspecting sw has become more friendly in devtools, I believe this api no longer holds a tight cause to be in the core. Make sure to run a deprecation cycle PR in 5.x before merging this PR.

[release-clerk]

Release Notes Persisted

Removed hasServiceWorker and unregisterServiceWorker APIs from the WebContents modules.