Updates to calculate_xr and addition of tests

See merge request m300602/pyicon!11

pyicon/pyicon_tb.py: Added function rename_dimension_names to allow for unique dimension nams in data and grid file.

pyicon/pyicon_tb.py: Moved rename_dimension_names to pyicon_tb.py. This however needs to be optimized.

pyicon/pyicon_calc_xr.py: Fixed typo and removed value error if dimensions of vector does not contain same dims as dz (e.g. to allow also time dim) in xr_edges2cell.

Fixed a typo in the pyicon_calculate_xr file

See merge request m300602/pyicon!9

pyicon/quickplots/qp_compare.py: Allow for optional reading of simulation namelist to avoid errors when namelist cannot be found.

pyicon/pyicon_tb.py: Added option for automatic fpath_ckdtree recognition. Added option in Triangulaiton to shift grid wrt dateline.

pyicon/pyicon_plotting.py: Added new plotting object to facilitate generation of axes and passing them to plotting routinse.

This reverts commit e9db8c32.

This reverts commit bb3e5552.