postgresstore: pagination does not work with multi evidences

[alexppxela]

Expected behavior

Pagination does not care about the number of evidences

Actual behavior

If pagination truncates evidences of the same link, pagination will return a segment with partial evidences. Client will ask for more segments (offset incremented) and will retrieve a segment with the same link with other evidences

Steps to reproduce the behavior

• Tables:
  • links

link_hash	map_id	process
123...123	"FOO"	"FAIL"
ABC...ABC	"BAR"	"FAIL"

• evidences

link_hash	provider
123...123	"btc:test3"
123...123	"btc:main"
123...123	"eth:Ropsten"

Results:

FindSegments(SegmentFilter{
    Pagination: Pagination{
        Offset: 0,
        Limit:  2,
    },
    Process: "FAIL",
})

Will return 123...123

FindSegments(SegmentFilter{
    Pagination: Pagination{
        Offset: 2,
        Limit:  2,
    },
    Process: "FAIL",
})

Will return 123...123 and ABC...ABC