fix(EMS-4130): broker zero addresses url, minor tech improvements

[ttbarnes]

Introduction ✏️

This PR fixes an issues where the UI's "Broker - zero addresses" URL was incorrect.

Also introduces some technical alignments regarding tests and documentation.

Resolution ✔️

• EMS-4130: Update BROKER_ZERO_ADDRESSES_ROOT constant.
• EMS-4131: Replace instances of e.g test('it should ... with it('should ...
• Update some UI GQL call error handlings that incorrectly had "network error" in some console errors.
• Update some UI validation functions to use formBody param, instead of responseBody.
• Simplify some UI validation functions documentation.

Miscellaneous ➕

• Fix some typos.
• Replace instances of "should display" with "should render".
• Minor task function documentation improvements.