Make state.show_{highstate,lowstate,sls} work with PyDSL

PyDSL needs an active HighState. If you have any sls file that uses the "pydsl" renderer you cannot use state.show_highstate, state.show_lowstate and state.show_sls at the moment.
Pushing the HighState on the active queue fixes this.
Merge pull request #6332 from d--j/patch-1

Make state.show_{highstate,lowstate,sls} work with PyDSL