Correction basics, updated DSSC device

First order of business: reviewing and merging the base class structure (BaseCorrection plus some aspects of calcat_utils.py and BaseGpuRunner as it applies to DSSC device). This MR is based on running git-filter-repo on add-agipd-device (branch used to get to AGIPD field test stage) to get rid of the following distracting changes which should optionally be reviewed and merged individually later:

• Small tweaks to Manager
  • Will be needed for properly instantiating correction devices
• scenes.py
  • Will need something to import for devices to work
  • Will only need full version for automatic scenes
• AGIPD device
• ModuleStacker (will hopefully not be relevant for next run)
• ShmemToZMQ
• Some rudimentary tests

Main class structure:

• BaseCorrection is base class of correction devices (Karabo bound devices), sets up common schema elements and does most shared Karabo stuff.
  • Subclasses: AgipdCorrection and DsscCorrection
  • There are a some class attributes the subclasses must set.
  • There are some things (like schema extensions) the subclasses have to do on their own.
• BaseGpuRunner is base class of the objects which handle all GPU interaction.
  • Subclasses: AgipdGpuRunner and DsscGpuRunner
  • A {}GpuRunner lives inside a {}Correction, but does not know about this (not tightly integrated into Karabo device).
    • It holds all its own buffers, can cleanly be deleted and reinstantiated.
    • It can be tested independently.
  • In agipd_gpu.py (home to AgipdGpuRunner), there are also some enums. Of particular importance is CorrectionFlags which is used both to give bit mask to kernel for enabling / disabling correction steps, but also to generate part of the device schema.
  • Each GPU runner class has a .cpp file with a correction kernel.
• BaseCalcatFriend (in need of more serious name) handles interaction with CalCat.
  • Subclasses: AgipdCalcatFriend and DsscCalcatFriend (all living in calcat_utils.py for now).
  • Similar to Philipp's prototype CalCat API wrapper, but these wrap themselves around the device schema for constant parameters (tight integration into Karabo device).
  • Specifically, a {}CalcatFriend manages the nodes constantParameters and foundConstants on its correction device (both to get parameters for querying and to set IDs and statuses when it's working).
  • Subclasses mostly serve to set up condition and constant mapping for a given detector.
  • In calcat_utils.py, there are also enums like AgipdConstants which list all the constants to fetch - also relevant for generation of device schema (see ex. _add_status_schema_from_enum).
  • They expect a secrets file for CalCat. By default, will look in ${KARABO}/var/data/calibration-client-secrets.json.