Increase Catalyst Signed Document verification during testing.

[Mr-Leshiy]

Summary

Modify the existing signed_doc/tests by using build_verify_and_publish instead of .inspect(|v| provider.add_document(v).unwrap())?.
This would increase reliability and verifiability of our tests, because it would properly verify each document before putting into the TestCatalystProvider.
So it would not violate our main current assumption, that everything what's coming from provider is valid.

Description

For each test file create a separate PR

• brand_parameters.rs
• brand_parameters_form_template.rs
• campaign_parameters.rs
• campaign_parameters_form_template.rs
• category_parameters.rs
• category_parameters_form_template.rs
• contest_ballot.rs
• contest_ballot_checkpoint.rs
• contest_delegation.rs
• contest_parameters.rs
• contest_parameters_form_template.rs
• proposal.rs
• proposal_comment.rs
• proposal_comment_form_template.rs
• proposal_form_template.rs
• proposal_submission_action.rs
• rep_nomination.rs
• rep_nomination_form_template.rs
• rep_profile.rs
• rep_profile_form_template.rs