orientation and coordinate validation

Iteration on GRIS coordinates from headers without cross-correlation

• Reworked _coords_from_simple_header method of GrisFitsFile with updated code and better comments
• Added function for expanding coordinates from a point to a slit to kis_tools.gris.util
• Added function for calculating parallactic angle to kis_tools.gris.util
• Added function for calculating slit orientation according to lucia to kis_tools.gris.util
• Reworked slit_orientationmethod of GrisFitsFile

Changes to GrisRun:

• added from_date_run classmethod to create an instance from a date, run combination (relies on /dat/sdc/gris as a data source)
• added maps_dict property to iterate over lists of files per map

Slit Orientation Validation

• updated slit orientation analysis: slit_orientation_study.ipynb

Header Translation

• added -r option to allow translating single runs

General Cleaning

• removing old script directories from grissubmodule
• Fixing a mixup between longitude and latitude in gregor_coords
• Added constants for GRIS stepsize
• Adding angle normalization utility

Testing

• Added tests for slit coordinate calculation, checking against the results of a cross correlation file works