Decided with invalid value should be rejected

[MatheusFranco99]

Issue from the comment:

Why is a decided message with invalid data considered valid? https://github.com/ssvlabs/ssv-spec/blob/main/qbft/spectest/generate/tests/tests.ControllerSpecTest_qbft_controller_decide_invalid_value_(should_pass).json
GitHub

In my view: this looks like a very old test, which probably followed the principle that "since the committee decided (bc the signatures are valid and a quorum is reached), then assume it as correct". But I also don't agree with such behaviour and we should fix it by adding a check that doesn't accept a message, even if decided, with an invalid value.

[github-actions]

This issue has been marked as stale due to 60 days of inactivity.