GO-4284 Remove Relation links

[KirillSto]

https://linear.app/anytype/issue/GO-4284/get-rid-of-relation-links

• remove relationLinks from state. Now list of relations is calculated based on details
• relationLinks are depricated in Snapshots
• relation addition means detail addition with Null value
• relation removal means detail removal
• relationLinks used to carry relation format. Now format is fetched from object store
• on state build empty details are not ignored anymore
• We do not generate ChangeRelationAdd and ChangeRelationRemove changes anymore
• RelationLinks are removed from responses of History, ObjectView and ObjectOpen rpcs

[github-actions]

New Coverage	50.7% of statements
Patch Coverage	60.6% of changed statements (354/584)

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^{Coverage provided by https://github.com/seriousben/go-patch-cover-action}