Wrong simplified changes list on update operation

[konard]

konard@MacBook-Pro-Konstantin link-cli % dotnet run --project Foundation.Data.Doublets.Cli -- '() ((1 2) (2 1))' --changes --after      
() ((1: 1 2))
() ((2: 2 1))
(1: 1 2)
(2: 2 1)
konard@MacBook-Pro-Konstantin link-cli % dotnet run --project Foundation.Data.Doublets.Cli -- '((($index: $source $target)) (($index: $target $source)))' --changes --after
((1: 1 2)) ()
((1: 1 2)) ((1: 2 1))
((2: 2 1)) ((2: 1 2))
(1: 2 1)
(2: 1 2)

[konard]

This bug is due the fact that unique links are forbidden in current version of data store.

But we can actually remove all previous versions of matched links and create only new ones, that might help ensure that in no point in time there are conflicts between existing links.

Yet it would be much simpler if this data store supported duplicates as in the links theory.