Fix: ensure consistent content in reputer value bundle

[amimart]

Purpose of Changes and their Description

Add some checks upon reputer ValueBundle, please review carefully these added checks to ensure they don't prevent allowed inputs.

Here are the added stateless validations when constructing the bundle:

• No duplicate inferers;
• No duplicate forecasters;
• Identical inferers in InfererValues and OneOutInfererValues;
• Identical forecasters in ForecasterValues, OneOutForecasterValues and OneInForecasterValues;
• OneOutInfererForecasterValues contains all forecasters, and all inferers for each;

As these checks ensured upon submission, I've removed some validations that were made in the reputer nonce closing.

Are these changes tested and documented?

• If tested, please describe how. If not, why tests are not needed.
• If documented, please describe where. If not, describe why docs are not needed.
• Added to Unreleased section of CHANGELOG.md?

[amimart]

Closing in favour of #812