Parser integrate: read pvt and grid

this adds code to read the all pvt and grid properties used by autodiff's sim_fibo_ad from the new parser. I just mostly copied and adapted the old code, so in the future this can receive some cleanups.

Be aware: This PR is for the opm-parser-integrate branch and depends on OPM/opm-parser#72 as well as on OPM/opm-core#451.