feat: filter process instances by multiple variables

[HMubaireek]

Description

filter process instances by multiple variables

{
  process(key: 2251799813712348){
    key
    processInstances(variablesFilter: {
      variables : [
      {
        name: "receiver", 
        value:"\"x@gmail.com\"",
        comparisonOperation: EQUALS
      },
      {
        name: "receiver", 
        value:"\"khaled.jabari@cntxt.com\"",
        comparisonOperation: EQUALS
      }          
      ],
      filterOperation: OR
    }
    ) {
      totalCount
      nodes {
        key
        variables(globalOnly: true){
           name
          value
        }
      }
    }
  }
}

Related issues

closes #
camunda-community-hub#16