Add camera pointing tools to GUI

[hdevillepoix]

to do

• Have an "Astrometry" or "Pointing" tab
• Drop-down menu that lets the user choose a night folder path (latest or latest_prev by default).
• Run astrometry button (linked to calibrate_non_tracking_observation_run)
• Could even put another option "take picture", save it in a temp folder, and calibrate it (using ​plate_solve_image), of limited use except when we are trying to accurately point those astro-ssa cams.
• Some way of indicating that calibration is running, and when it's finished.
• Display the pointing diagnosis (especially alt-az values), using ​camera_pointing_diagnosis
• A button with decent amount of warnings that overwrites /opt/dfn-software/dfnstation.cfg with the found solution​ (using write_calib_info_to_cfg_file)​​, maybe make a backup ​​first with date.

calibration of a file

• takes a raw file as input (it must have a dfnstation.cfg file in the same folder), or a fits.
• raises AstrometricSolutionNotFound if it can't solve.
  camera_env = ​​plate_solve_image(image)

calibration of a folder

• tries to find a suitable calibration image in a folder. might want to use it on or latest or latest_prev.
• raises AstrometricSolutionNotFound if it runs out of images without having found a nice starry one.
  camera_env = on_board_astrometry.calibrate_non_tracking_observation_run(observation_run_folder)

pointing diagnosis

• return a dictionary (values in degrees):
  {'RA_zenith' , ''Dec_zenith' , 'Alt_pointing' , 'Az_pointing' , 'RA_pointing' ,'Dec_pointing' }
  on_board_astrometry.​​camera_pointing_diagnosis(camera_env)

update calibration parameters (center/north pixels...) in dfnstation.cfg file

• it checks that the target dfnstation.cfg observatory coordinates are close to the ones associated with calibration image. -> raises NotTheSameSpotMate if not.
  on_board_astrometry.​​write_calib_info_to_cfg_file(io_cfg_file, camera_env)