scrub/sophisticated-jwst-prod-naming (#56)

* global vars for nan, true, false variations

* delete commented out code

* remove new column names log statement

* docstrings, add mode attr for scraping method, make level3_types a property

* docstrings, xcol_order is a property, add additional properties expdata and source_based

* revised naming and exposure grouping schema for l3 products

* additional nan variations to check in categorical nandler

* input_data is a property, docstrings, nircam detector grouping (for future use)

* tso_ami_coron is a property

* add band encodings to config, update gencols and colorder

* update scrub tests

* update changelog

* added line comment

* instr is at index 2 position

CHANGES.rst

@@ -20,6 +20,9 @@ enhancements
     - save tx_file name with "-{expmode}" to differentiate between image and spec normalization params
     - rename target attributes: y_img_train, y_img_test to y_reg_train, y_reg_test
 
+- `preprocessor.scrub.JwstCalScrubber` more sophisticated exposure grouping and L3 product naming [#56]
+
+
 bug fixes
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