fix: Translate nested or/and constraint properly

[skycastlelily]

No description provided.

[skycastlelily]

This mr fixes the following tmt issue:

If users specify a hardware with nested and/or ,say:

hardware:
      or:
        - hostname: == dummy1.redhat.com
        - or:
            - hostname: == dummy2.redhat.com
            - or:
                - hostname: == dummy3.redhat.com
                - hostname: == dummy4.redhat.com

They will get a job containing the following hostrequires

      <hostRequires>
        <and>
          <or>
            <hostname op="==" value="dummy1.redhat.com"/>
            <or/>
          </or>
        </and>
      </hostRequires>