graphql: add destinationDisplayInfo query

[mastercactapus]

Description:
Adds the destinationDisplayInfo query under the dest-types experiemental flag.

Run with make start EXPERIMENTAL=dest-types

Describe any introduced API changes:
Adds Query.destinationDisplayInfo for providing information for displaying a destination in the UI.

Additional Info:

• Updated slack package to provide Team including IconURL
• Added helper methods for getting field values from DestintationInput
• Added destinationDisplayInfo to schema behind experimental flag directive
• Added TeamID to usergroup metadata

Example Query:

{
  sms: destinationDisplayInfo(input:{
    type: "builtin-twilio-sms",
    values: [{
      fieldID: "phone-number",
      value: "+17635550123"
    }]
  }) {
    iconURL
    iconAltText
    text
    linkURL
  }
  
  email: destinationDisplayInfo(input:{
    type: "builtin-smtp-email",
    values: [{
      fieldID: "email-address",
      value: "[email protected]"
    }]
  }) {
    iconURL
    iconAltText
    text
    linkURL
  }
  
  webhook: destinationDisplayInfo(input:{
    type: "builtin-webhook",
    values: [{
      fieldID: "webhook-url",
      value: "https://google.com"
    }]
  }) {
    iconURL
    iconAltText
    text
    linkURL
  }
  
  
  user: destinationDisplayInfo(input:{
    type: "builtin-user",
    values: [{
      fieldID: "user-id",
      value: "446be959-961e-4815-9a63-62dc045e86e3"
    }]
  }) {
    iconURL
    iconAltText
    text
    linkURL
  }
 
  rotation: destinationDisplayInfo(input:{
    type: "builtin-rotation",
    values: [{
      fieldID: "rotation-id",
      value: "55d54b6c-2b53-43b2-98a4-1fa5442e8495"
    }]
  }) {
    iconURL
    iconAltText
    text
    linkURL
  }
}