Fix bugs in metrics calculations for Payments page - Analytics V2 dashboard:

• Successful Payments Distribution and Failure Payments Distribution: Exclude the dropoffs from the denominator while calculating the rates
• Failure reasons: Remove limit by clause and extract data for all error_reasons
• Payments lifecycle: Update the sankey response structure to look like this:

  { 
    "count":"25",
    "first_attempt":0,
    "status":"requires_payment_method",
    "refunds_status":null,
    "dispute_status":null
  }