chore: remove deprecated functions

[Justintime50]

Description

• Adds tracking_codes to tracker list function
• Removes deprecated functions
  • TimeInTransit.getSmartRateAccuracy (use TimeInTransit.getSmartrateAccuracy instead)
  • paymentMethod.all (use billing.retrievePaymentMethods instead)
  • shipment.getSmartrates (use shipment.smartrates instead)
  • String overload for shipment.lowestSmartRate, 3rd param requires a valid SmartrateAccuracy
  • user.apiKeys (use apiKey.retrieveApiKeysForUser instead)
  • utilities.getLowestSmartRate (use utilities.findLowestSmartrate instead)

Testing

NA

Pull Request Type

Please select the option(s) that are relevant to this PR.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Improvement (fixing a typo, updating readme, renaming a variable name, etc)