HIT L2 - ISTP compliance updates (#1852)

* Update Data_type to remove hyphen between macro and pixel for consistency with logical source value

* Address comments from Andriy - fix typo in delta var attributes. Remove DEPEND_1 in energy mean variables. Remove DISPLAY_TYPE for support data variables

* Set dynamic threshold state data type to int8

* Set dynamic threshold state data type to int8 during decommutation of L0 packet

* Implement additional suggested changes from Andriy

-Add SPASE metadata to support data variables
-Update energy variable units to energy per charge
-Remove display type for uncertainty variables
-Update energy variable CATDESC
-Update dynamic threshold state fillval

* Add DELTA_MINUS_VAR and DELTA_PLUS_VAR to energy mean variables

* Update valid min/max and scalemax to floats to match data variable data type. Replace DEPEND_0 with DEPEND_1 for a few energy variables to match other energy variable attributes. Fix typo. Update format for energy variables

* Round energy mean to one decimal place

* Update label dims to have itself as the value. This avoids cdflib adding DEPEND_1 as an attribute to the label which isn't needed for metadata variables. Checking with Andriy for clarification on dimensions for labels

* Update unit test to reflect update in label dims

* Change dtype to uint8 for dynamic threshold state since it's never negative

* Update energy mean rounding to 3 decimal places. Replace abbreviation for nucleon with full spelling in CATDESC attributes where needed for clarity

* Expand FORMAT for energy mean labels to A6 to cover possible values

Author: vmartinez-cu

imap_processing/cdf/config/imap_hit_global_cdf_attrs.yaml

@@ -70,7 +70,7 @@ imap_hit_l2_summed-intensity:
 
 imap_hit_l2_macropixel-intensity:
     <<: *instrument_base
-    Data_type: L2_macro-pixel-intensity>Level-2 Macro Pixel Intensity
+    Data_type: L2_macropixel-intensity>Level-2 Macro Pixel Intensity
     Logical_source: imap_hit_l2_macropixel-intensity
     Logical_source_description: IMAP Mission HIT Instrument Level-2 Macro Pixel Intensity Data.