Clear required flag for isBlocked fields + remove some fields.

[isoos]

• Fix integrity check wrt. blocked packages #8336
• We cannot remove the isBlocked fields yet, first we need to move away from deployments that use it as required. This PR prepares for that.
• The blocked and blockReason fields can be removed already.
• Note: I've also noticed some differences in how we treated isBlocked and isModerated, I'll address those in follow-up PRs in smaller bits, as it raised a few questions on which behavior we want to follow.