Rewrite zabbix returner to be more useful

[OrangeDog]

Port of saltstack/salt#62055

Still no tests, but don't want to lose the code.

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[OrangeDog]

I should also put this example somewhere useful

items:
  - name: 'Salt: state.apply'
    type: TRAP
    key: salt.return.state.apply
    delay: '0'
    history: 14d
    trends: '0'
    value_type: TEXT
    description: 'Return data from the state.apply function'
    tags:
      - tag: component
        value: salt
    triggers:
      - expression: 'find(//salt.return.state.apply,,"like","(changed=")=1'
        name: 'Salt state changed'
        priority: INFO
        type: MULTIPLE
        tags:
          - tag: scope
            value: notice
      - expression: 'find(//salt.return.state.apply,,"regexp","Failed:\s*0")=0'
        name: 'Salt state failed'
        priority: HIGH
        tags:
          - tag: scope
            value: availability
      - expression: 'nodata(//salt.return.state.apply,1d)=1'
        name: 'Salt state is stale'
        priority: WARNING
        tags:
          - tag: scope
            value: security

Alternatively, use the json output and create dependent items with some JSONPath.