Add missing schemas

[rspeed]

• nel / nel-report (legacy): Network Error Logging
• expect-ct
• expect-staple

Possibly split these into a separate task later:

• deprecated: Use of a deprecated API.
• intervention: The browser prevented some action.
• crash: The browser process crashed while on the site.
• Javascript errors?
• CSS / HTML parsing errors?

[rspeed]

Accidentally closed in commit comment.

[rspeed]

Expect-CT and Expect-Staple need custom schema definitions.