flow: better config management

config.json

@@ -4,19 +4,15 @@
     "sample_ship": "Vessel name",
     "sample_operator": "Operator's name",
     "sample_sampling_gear": "net",
+    "sample_gear_net_opening": 40,
     "acq_id": 1,
     "acq_instrument": "PlanktonScope v2.2",
     "acq_celltype": 200,
     "acq_minimum_mesh": 10,
     "acq_maximum_mesh": 200,
-    "acq_min_esd": 20,
-    "acq_max_esd": 200,
     "acq_volume": 1,
-    "acq_magnification": 0.94,
     "acq_fnumber_objective": 16,
-    "acq_camera": "Pi Camera HQ",
     "object_depth_min": 0,
     "object_depth_max": 1,
-    "process_pixel": 1.19,
     "process_id": 1
 }