Passing probabilistic data through Python embedding does not work.

[JohnHalleyGotway]

This issue was raised via MET-Help:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=92694

The user passed data with python embedding to Point-Stat and set "prob = TRUE;" in the config file, but no probabilistic output was produced.

The problem existing in the VarInfoPython::set_dict() function in var_info_python.cc. It fails to parse the "prob" setting from the input dictionary.

In the master_v8.1 bugfix branch (for met-8.1.2), fix this by updating that function in the python library.

In the develop branch (for met-9.0), fix this by factoring the parsing of "prob" output from the derived libraries (vx_data2d_grib, vx_data2d_grib2, vx_data2d_python, vx_data2d_nc_met, vx_data2d_nccf, vx_data2d_nccf) and do it once in the base class (VarInfo::set_dict()) instead.

[JohnHalleyGotway]

Fixed in master_v8.1 and the develop branches.