[SERVICES-2466] Fix 'hasPreviousPage' field on paginated queries

[mad2sm0key]

Reasoning

• the hasPreviousPage field of the PageInfo model on paginated queries is always false

Proposed Changes

• override the values provided by the util function connectionFromArraySlice from the graphql-relay package

How to test

A paginated query (filteredTokens / filteredPairs / filteredStakingFarms) using forward cursor pagination like below, should correctly return true for the hasPreviousPage field

query {
  filteredTokens(
    filters:{}
    pagination:{
      first:10
      after:"YXJyYXljb25uZWN0aW9uOjk="
    }
  ) {
    edges {
      cursor
      node {
        identifier
        price
      }
    }
    pageInfo {
      hasNextPage
      hasPreviousPage
      startCursor
      endCursor
    }
    pageData {
      count
      limit
      offset
    }
  }
}

[cfaur09]

tested 🟢